Hi

I am sorry but I do not understand your question. How can we help you with Firefox?

This sounds like an extension. Is Capital One Shopping listed on the drop-down from the Extensions button (the puzzle piece button next to the main menu button)?

Yes, it is listed

Right-click the extension and click Remove extension.

No, it is not listed

At the bottom of the panel, click "Manage extensions" to load the Add-ons page. Find the unwanted extension, then use the ... next to the enable/disable switch to access Remove.

Ref. Manage your extensions using the extensions button in the toolbar

Success?