I'm here to help ensure you're able to add a user, rrojas1.
Are you getting an error when adding users? If so, there could be a data corruption on your QuickBooks Online files. You can clear the browser's cache and cookies to refresh the website.
If you're seeing a user limit message, it’s because QuickBooks Online has a maximum number of users depending on your subscription. Check out this link: What are usage limits in QuickBooks Online? to see what you can do to add user.
Also, one of the requirements to add a user is to log in to QuicBooks as the master or company administrator.Once done, follow the steps below:
Choose the Gear icon at the top, then select Manage Users.