Dear Erica Wagner,
Thank you for using Microsoft products and posting in the Microsoft Support Community.
I realise you want to turn off copilot on outlook, please point out if I'm misunderstanding.
What you mentioned about turning it off via the File tab at the top of the outlook page is limited to classic Outlook. from the screenshot you provided, it looks like you are using new Outlook. for the interface of classic Outlook, please refer to the image below:


You can open classic Outlook and follow the steps in the official article to turn off copilot.
How to turn off Copilot in Microsoft 365 Family and Personal subscriptions - Microsoft Support

Allow me to explain to you that Microsoft has recently been experimenting with new Microsoft 365 subscriptions, including the AI tool Copilot, to meet the needs of different users. As a result, users in certain regions may notice some changes in Microsoft 365 and the addition of Copilot to Microsoft 365 plans. I fully understand the inconvenience this may cause, especially for some users who do not wish to use this AI feature.
If you still want to use new Outlook and turn off copilot, you can contact Chat Support directly to modify your Microsoft 365 Classic subscription that does not include Copilot.
Visit this website: Contact - Microsoft Support
Type in your problems in the search box there.( For instance, contact support.)
Now click Get help, and Select Contact Support below.
Go to the Products and services tab, and choose either Microsoft 365 and Office category
On the Category tab, choose Manage My Subscription .
Go to Confirm.
Choose to chat with a support representative or request a callback.


Tips: If after completing the steps above, the page is not available, it may be a non-working day or non-working time, and it is recommended that you contact them during the page prompted working hours.
Thank you for your patience and support.
Best Regards
Vivian.Y - MSFT | Microsoft Community Support Specialist