If you see the Payment Methods menu choice, then you are running a supported version.

Likely the situation is that you are logged into Adagio Receivables as a user belonging to a security group that doesn't have access to that function. If you have the rights in Adagio to modify security groups, then you should do so for those groups to allow access to Payment Methods. (File, Edit Groups).

The same scenario is likely for email cover sheets - security and access needs to be enabled.