Let me help you add a new user to your QuickBooks Online account, holly.tang.
The admin user of the account can invite or add you as a new user by going to Gear icon (⚙). Let me show you how:
Then, the new user will now get an email from firstname.lastname@example.org on how to create the account.
Here's more information on this article: Add, delete, or change
Feel free to let me know if you have additional questions. I'm always here to answer them and help you out with other concerns. Take care and have a wonderful day.