Good day, kappahelp.
To remove a company from your profile, you will need to open it. Then, go to the Accountants section and delete the wrong email from there. Here's how:
You can see the steps in my screenshots below. Let me also share this guide about adding and removing accountants: Add Or Remove An Accountant User In QuickBooks Online.
You can always reply to this thread if you have follow-up questions.