There is an Administration module under App store modules inside your project under Project explorer, inside it you will find a page User Management > Admin ‘Account_Overview’ add it to the admin navigation this will help you add/delete users. if its something different that is required please let me know.
In MenndixSSO, adding users should be done from the Developer Portal, Publish your application (Mendix Studio) then → App Settings (lower left corner of your app ”gear icon”) then → Manage Users (here you invite your Mendix users, select the role and send invitation)
Then they need to approve the invitation and login with their Mendix account credentials.
the process is similar to inviting to a project on Mendix Team Server.
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