UDP never lets anyone grant more than they have. If a permission, a property or a kind of data is outside your own access, you can't give it to a role or a user, and the option is disabled.
You might see:
Cannot assign property access you do not have
Cannot assign a data domain you do not have access to
Cannot assign a role that grants permissions you do not have
Inherited from your own access, above the property filters, when your own access is limited.
Ask an admin with wider access to make the change, or contact us.