terraform Error reading EFS Mount Target too many results: wanted 1 got 3

Question

Trying to get the security group associated with the EFS mount target but it gives below error:

Error reading EFS Mount Target too many results: wanted 1 got 3

data "aws_efs_mount_target" "by_id" {
  file_system_id = aws_sagemaker_domain.example.home_efs_file_system_id
}

output "sg_id" {
  value = tolist(data.aws_efs_mount_target.by_id.security_groups)
}