How do I use two request parameters to set a MessageGroupId when integrating API Gateway V2 (HTTP) and an SQS FIFO queue?

Question

I've set up an integration on my API Gateway V2 (HTTP) to send a message to my SQS FIFO queue. I need to set the MessageGroupId to use two properties that exist on the request body. The requests sent to API Gateway will be POST requests with a JSON body. I want to use the $request.body.orgKey and $request.body.entityType to create my MessageGroupId but I've been unsuccessful.

When sending requests to the API Gateway with MessageGroupId of the RequestParameters set to MessageGroupId: '${request.body.orgKey}${request.body.entityType}', the request fails and the logs show the following error message:

"Unable to resolve property MessageGroupId from source ${request.body.orgKey}${request.body.entityType}. Please make sure that the request to API Gateway contains all the necessary fields specified in request parameters."

When I use just one property, e.g. ${request.body.orgKey}, the message is enqueued successfully.

My CloudFormation object:

APIGatwaySQSIntegration: {
    Type: 'AWS::ApiGatewayV2::Integration',
    Properties: {
        ApiId: {
            Ref: 'ApiGateway'
        },
        CredentialsArn: '${self:provider.iam.role}',
        IntegrationType: 'AWS_PROXY',
        IntegrationSubtype: 'SQS-SendMessage',
        PayloadFormatVersion: '1.0',
        RequestParameters: {
            QueueUrl: {
                Ref: 'webhooksQueue',
            },
            MessageBody: '$request.body',
            MessageDeduplicationId: '$request.body.eventId',
            // Does not work
            MessageGroupId: '${request.body.orgKey}${request.body.entityType}',
            // Works but not what I need
            // MessageGroupId: '$request.body.orgKey',
        }
    }
},```

Answer 1

Ugh... I wasn't including entityType in the request body... The cloudformation template was fine