Thanks @jbardin for your answer.
I was trying to use the following target:
terraform plan target="module.sso_roles.aws_iam_policy_attachment.admin-policy-attachment"
Plan: 0 to add, 3 to change, 0 to destroy.
The changes that were planned to be made, were correct.
As I mentioned, the apply didn’t execute any change.
Reviewing the output from plan I saw that Terraform was going to perform actions in the aws_iam_policy that I modified, so I changed the target to the policy, and Terraform now applied correctly the change.
terraform apply target="module.sso_roles.aws_iam_policy.admin-policy"
Apply complete! Resources: 0 added, 3 changed, 0 destroyed.
Thanks for the clarification in the use of -target