Update configuration.md (#377)

* Update configuration.md

* Update configuration.md

* Update configuration.md

Author: theletterf

docs/reference/edot-sdks/php/configuration.md

@@ -40,7 +40,7 @@ The most important OpenTelemetry options you should be aware of include:
 
 | Option(s)                                                                                                                     | Default                 | Accepted values                                 | Description                                                                                                                                                                                                |
 | ----------------------------------------------------------------------------------------------------------------------------- | ----------------------- | ----------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| [OTEL_EXPORTER_OTLP_ENDPOINT](https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/#otel_exporter_otlp_endpoint) | `http://localhost:4318`   | URL                                             | Specifies the OTLP endpoint to which telemetry data should be sent.                                                                                                                                        |
+| [OTEL_EXPORTER_OTLP_ENDPOINT](https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/#otel_exporter_otlp_endpoint) | `http://localhost:4318`       | URL                                             | Specifies the OTLP endpoint to which telemetry data should be sent.                                                                                                                    |
 | [OTEL_EXPORTER_OTLP_HEADERS](https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter/#otel_exporter_otlp_headers)   |                         | String of key-value pairs                       | Key-value pairs to be used as headers (e.g., for authentication) when sending telemetry data via OTLP. Format: `key1=value1,key2=value2`.                                                                  |
 | [OTEL_SERVICE_NAME](https://opentelemetry.io/docs/languages/sdk-configuration/general/#otel_service_name)                     | `unknown_service`       | String value                                    | Sets the value of the [service.name](https://opentelemetry.io/docs/specs/semconv/resource/#service) resource attribute.                                                                                    |
 | [OTEL_RESOURCE_ATTRIBUTES](https://opentelemetry.io/docs/languages/sdk-configuration/general/#otel_resource_attributes)       |                         | String of key-value pairs                       | Key-value pairs to be used as resource attributes. See [Resource SDK](https://opentelemetry.io/docs/specs/otel/resource/sdk#specifying-resource-information-via-an-environment-variable) for more details. |
@@ -135,8 +135,7 @@ The following settings control Central configuration management through OpAMP.
 
 | Option(s)                             | Default                        | Accepted values                                                                               | Description                                                                                                                                                                 |
 | ------------------------------------- | ------------------------------ | --------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| ELASTIC_OTEL_OPAMP_ENABLED            | `false`                          | `true` or `false`                                                                                 | Turns on the OpAMP client. When set to `true`, the SDK establishes a connection with an OpAMP-compatible server for remote configuration and control. |
-| ELASTIC_OTEL_OPAMP_ENDPOINT           | http://localhost:4320/v1/opamp | Valid HTTP or HTTPS URL. For example, `http://host:port/path`                                      | The HTTP or HTTPS endpoint of the OpAMP server. Required if OpAMP is enabled.                                                                                                        |
+| ELASTIC_OTEL_OPAMP_ENDPOINT           |              | Valid HTTP or HTTPS URL.                                          | The HTTP or HTTPS endpoint of the OpAMP server. Required to enable Central configuration management. For example, `http://localhost:4320/v1/opamp`. Endpoint must always end with `/v1/opamp`.                                                                                       |
 | ELASTIC_OTEL_OPAMP_HEADERS            | -                              | Comma-separated key-value pairs. For example, `Authorization=Bearer xxxxxx,UserData=abc`            | Custom HTTP headers to send with the OpAMP connection request. Use key-value pairs separated by commas.                                                                   |
 | ELASTIC_OTEL_OPAMP_HEARTBEAT_INTERVAL | 30s                            | Integer number with time duration. Optional units: ms (default), s, m. It can't be set to 0. | The interval between heartbeat messages sent to the OpAMP server. This also determines how often the agent will poll for updated configuration, if available.               |
 | ELASTIC_OTEL_OPAMP_SEND_TIMEOUT       | 10s                            | Integer number with time duration. Optional units: ms (default), s, m. It can't be set to 0. | Timeout duration for sending messages to the OpAMP server.                                                                                                                  |