I can share the steps on how you can transfer the Master Admin role in QuickBooks Online. Please note that you must be the primary admin of the company file to change the primary admin role.

Follow these steps:

1. Tap Settings ⚙ then Manage users.
2. Find the user you want to make the primary admin.
3. Look in the Role column and make sure they are listed as Admin. If they’re not, select Edit to change their role to admin.
4. Click the small arrow ▼ in the Action section. Then, select Make primary admin.
5. Wait until you receive the verification code sent to the phone number or email on file for your account. Enter the code and select Continue.
6. Press Make primary admin again to confirm the change.
7. Once done, sign out of QuickBooks.

There are also instances that the current primary admin might no longer be with the company. In cases like this, you can request to be the primary admin. 

See this link to learn more about Master Admin transfer: Change the primary admin user in QuickBooks

Please post here again if there's anything else you need help with. I'll be more than happy to help you further with this. Have a good one!