Troubleshooting Cross Region Replication for Automated Backups with Terraform AWS RDS Module

I am using https://github.com/terraform-aws-modules/terraform-aws-rds/tree/master/modules module to enable cross region replication for Automated backups for MSSQL but I am not able to do so. I can only provision an RDS
This is what I have for the cross region replication for automated backups

  source                     = "/modules/db_instance_automated_backups_replication"
  version                    = "v4.7.0"
  source_db_instance_arn     = module.db.db_instance_arn
  kms_key_id                 = "kms_key_here"

  providers = {
    aws = aws.region2
  }
}```
TF is not able to resolve properly

https://registry.terraform.io/modules/terraform-aws-modules/rds/aws/latest/submodules/db_instance_automated_backups_replication shows an example on the side on how to reference a sub module