How to access private ECR repository images through terraform?

I have a private ECR repo in AWS Acc #1.

Multiple Terraform projects deploy to major cloud providers. ( AWS Acc #2, GCP Acc #1, etc).

How do I refer to the images stored in the private ECR repo when defining resources for other Terraform projects?

A use case can be:-

Suppose there is an Image Image #1 in AWS Acc #1, Now I need to use it for a lambda function in AWS Acc #2 So I'll define the resource as

resource "aws_lambda_function" "my_func" {
  function_name = "my-func"
  role          = aws_iam_role.iam_for_lambda.arn
  environment {
    variables = {
      UNIQUE_KEY = var.env_name
    }
  }

  package_type = "Image"
  image_uri = "{ACC_ID}.dkr.ecr.{REGION}.amazonaws.com/{IMAGE_NAME}:{TAG}"

  memory_size = 4096
  ephemeral_storage {
    size = 4096
  }
  timeout = 900
}

This does not work as the Image URI {ACC_ID}.dkr.ecr.{REGION}.amazonaws.com/{IMAGE_NAME}:{TAG} is not accessible.

It works fine if Image is in AWS Acc #1 and is being used in a lambda defined in AWS Acc #2.