Thanks for posting here. Let me show you how to invite a user.
Please follow these steps:
Go to the Gear icon and select Manage users.
Click the Add user, then select a user type.
Enter the details required, Save.
Please note that they will receive an invitation email. They'll need to accept it so they can create their own login credentials to access your account.
I also added these articles for more details on how to manage the users and if you wanted to add the tax preparer as an accountant: