Merge pull request #229 from nginx/internal/nginxaas-certs

docs: Add certificate doc for NGINXaaS for Google

Author: JTorreG

content/nginxaas-google/getting-started/ssl-tls-certificates/ssl-tls-certificates-portal.md

@@ -19,14 +19,42 @@ If you haven't already done so, complete the following prerequisites:
 - Access the portal visiting [https://console.nginxaas.net/](https://console.nginxaas.net/).
     - Log in to the NGINXaaS console with your Google credentials.
 
-### Add an SSL/TLS certificate
-
-
-### Edit an SSL/TLS certificate
-
-
-### Delete an SSL/TLS certificate
-
+## Add an SSL/TLS certificate to NGINXaaS
+- Select **Certificates** in the left menu.
+- Select {{< icon "plus">}} **Add Certificate**.
+- In the **Add Certificate** panel, provide the required information:
+
+    {{< table >}}
+   | Field                       | Description                  |
+   |---------------------------- | ---------------------------- |
+   | Name                        | A unique name for the certificate. |
+   | Type                        | Select the type of certificate you are adding. SSL certificate and key, or CA certificate bundle. |
+   | Certificate Import Options  | Choose how you want to import the certificate. Enter the certificate text or upload a file. |
+     {{< /table >}}
+
+- Repeat the same steps to add as many certificates as needed.
+
+### Use a certificate in an NGINX configuration
+
+To use a certificate in an NGINX configuration, follow these steps:
+
+- Select **Configurations** in the left menu.
+- Select the ellipsis (three dots) next to the configuration you want to edit, and select **Edit**.
+- Select **Continue** to open the configuration editor.
+- In your configuration, select {{< icon "plus">}} **Add File** and either choose to use an existing certificate or add a new one.
+    - If you want to add a new certificate, select **New SSL Certificate or CA Bundle** and follo the steps mentioned in [Add an SSL/TLS certificate to NGINXaaS](#add-an-ssltls-certificate-to-nginxaas).
+    - If you want to use an existing certificate, select **Existing SSL Certificate or CA Bundle** and use the menu to choose a certificate from the list of certificates you have already added.
+- Provide the required path information:
+
+    {{< table >}}
+   | Field                       | Description                  | Note |
+   |---------------------------- | ---------------------------- | ---- |
+   | Certificate File Path       | This path can match one or more ssl_certificate directive file arguments in your NGINX configuration. | The certificate path must be unique within the same deployment. |
+   | Key File Path               | This path can match one or more ssl_certificate_key directive file arguments in your NGINX configuration. | The key path must be unique within the same deployment. |
+     {{< /table >}}
+
+- Update the NGINX configuration to reference the certificate you just added by the path value.
+- Select **Continue** and then **Save** to save your changes.
 
 ## What's next