Hello there, @joe-stefan.
Let me share with you some of my ideas about managing your account in QuickBooks Online. You can invite a user in QuickBooks once you logged in as an Administrator. I recommend contacting your system administrator to check the error.
I've also provided steps on how to add a user to your account. Here's how:
- Go to the Gear icon.
- Select the Manage Users tab. Note: If you can’t select this, you don’t have permission to manage other users. Contact an admin user for help.
- Choose Add user.
- Select the user type you want to create.
- Enter your new user’s name and email address, then click Save.
For more steps, you can refer to this article: Add, delete, or change user access in QuickBooks Online
If you have follow-up questions, feel free to leave a message in the comment section. I'll be happier to help. Take care and have a great day!