This is how you add users in ApprovalMax: Go to the main menu, select your Organisation and open "Users page" under "Workflows and Settings" section. Click on the button and type in the user’s email address. You can enter multiple email addresses; ...
Adding a large number of users in a single step is indeed possible in ApprovalMax. Here's a detailed description of how you can achieve this: How can I add users in ApprovalMax?