How to implement an api policy with conditional <?:>

Terraform Providers AWS
1

hi guys ,

I am trying to set up a policy for my api with a condition as shown in my code below:

resource "aws_api_gateway_rest_api_policy" "api_policy" {
  rest_api_id = aws_api_gateway_rest_api.api_rest.id

  policy = var.is_regional ? jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Effect = "Allow"
        Principal = {
          AWS = var.aws_iam_authorize
        }
        Action = [
          "execute-api:Invoke",
        ]
        Resource = "*",
      }
    ]
    }) : jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Effect = "Allow"
        Principal = {
          AWS = var.aws_iam_authorize
        }
        Action = [
          "execute-api:Invoke",
        ]
        Resource = "*",
        Condition = {
          test     = "ForAnyValue:StringEquals"
          variable = "aws:sourceVpce"
          values   = [var.vpce-id]

        }
      }
    ]
    }
  )
}

but I still have a syntax error that appears and I follow the documentation well. when I make a plan I see that the policy is taken into account but when applying I have this error :

Error: setting API Gateway REST API Policy BadRequestException: Invalid policy document. Please check the policy syntax and ensure that Principals are valid.
│
│ with module.apigateway_identity.aws_api_gateway_rest_api_policy.api_policy,
│ on Modules/apigateway/main.tf line 158, in resource “aws_api_gateway_rest_api_policy” “api_policy”:
│ 158: resource “aws_api_gateway_rest_api_policy” “api_policy” {

do you have any idea ? is this feasible ?

thx for advance.