OneIdentityManager OnDemand - Disable CustomTargetSystem change password

Morning,
we are implementing password change on different types of custom target system. For other target systems, however, we want to disable the ability for the user to change the account password from the password reset portal.

For example, if I have an account on Goofy target system, which I don't want to support password change, I would like the possibility to change it from password reset portal not to appear.

How is it possible to do that?

Thank you,
Edilio