Fix terraform

Author: stevebux

infrastructure/terraform/components/api/README.md

@@ -34,6 +34,7 @@ No requirements.
 |------|--------|---------|
 | <a name="module_authorizer_lambda"></a> [authorizer\_lambda](#module\_authorizer\_lambda) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-lambda.zip | n/a |
 | <a name="module_domain_truststore"></a> [domain\_truststore](#module\_domain\_truststore) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-s3bucket.zip | n/a |
+| <a name="module_get_letter"></a> [get\_letter](#module\_get\_letter) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-lambda.zip | n/a |
 | <a name="module_get_letters"></a> [get\_letters](#module\_get\_letters) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-lambda.zip | n/a |
 | <a name="module_kms"></a> [kms](#module\_kms) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-kms.zip | n/a |
 | <a name="module_logging_bucket"></a> [logging\_bucket](#module\_logging\_bucket) | https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-s3bucket.zip | n/a |

infrastructure/terraform/components/api/module_lambda_get_letter.tf

@@ -1,4 +1,4 @@
-module "get_letters" {
+module "get_letter" {
   source = "https://github.com/NHSDigital/nhs-notify-shared-modules/releases/download/v2.0.20/terraform-lambda.zip"
 
   function_name = "get_letter"