In this section, you can to control other customization settings for Paid Memberships Pro plugin, like messages displayed to non-members, notifications etc.
Go to Memberships | Settings and click on the “Advanced” link. Then, customize as you want and, in the bottom of page, just click on the “Save Settings” button:
Detailed information about this topic can be found at https://www.paidmembershipspro.com/documentation/initial-plugin-setup/step-5-advanced-settings/