QuickBooks Self-Employed only supports two users. Let me explain.
Aside from you as the primary owner of the account, we can only add accountant access. This means QuickBooks Self-Employed is unable to add another user for the bookkeeper.
You'll want to upgrade your plan to QuickBooks Online so you can add more users and you'll have more accounting features. You can find the steps on how to switch and the link for the QuickBooks Online plans through this article: Switch from QuickBooks Self-Employed to QuickBooks Online. This includes the instructions on how to export the data and cancel your existing QuickBooks Self-Employed subscription to avoid double charges.
I'll be right here if you need more assistance with this. Thanks!