Your WP eMember plugin’s admin dashboard is only accessible to WP Admin users by default. There is an option in the plugin that you can use to give other WP User roles (example: editor, author etc.) access to the eMember plugin’s admin dashboard.
Enabling Dashboard Access for Other WordPress User Roles
Step 1) Go to the “Admin Functions” menu of the plugin.
Step 2) Scroll down to the “eMember Admin Dashboard Acess Permission” section.
Step 3) Select the desired role and save the permission.

WP users with and above that selected user role will now have access to the dashboard.
Also, to turn off this feature, just select “Admin” and then save the permission so only users with admin role can have access.
@Tom, The access to the admin dashboard comes from the WP user’s role. You can edit any WP user record (from the Users menu of WordPress) and downgrade the role to something like “subscriber”. You can read more about WordPress user roles on the official WordPress page:
https://codex.wordpress.org/Roles_and_Capabilities
In reference to “Giving Other WordPress User Roles Access to Your WP eMember Admin Dashboard”
If I no longer need to grant such access, how do I REMOVE access from non-admin to the WP eMember Admin Dashboard?