How do I diable the "Add X as an application for mailto links" prompt?

[szx]

Since Firefox 124 I've started seeing this annoying prompt on outlook.com every time I open it:

and closing it does not make any difference - on the next page load it opens again.

Is there a way to disable it permanently?

[jscher2000]

Hi, I'm only aware of one way to get rid of this prompt, which is to let Firefox add Outlook to your options for email links. There is no download involved, Firefox just adds the site's message compose URL to this list: https://support.mozilla.org/en-US/kb/change-program-used-open-email-links 

[Hamish]

Adding that this is extremely annoying to be spammed. Wasn't happening until this most recent update. No other browser is harassing me with this.

[rdimartino]

I was going to file a bug for this because Firefox it keeps popping up every page load no matter how many times I click the `x`. Joining the voices here to say this spam is annoying. For me the problem is the same but it's with "outlook.office.com" requesting the permission. Ideally, I'd like Firefox to respect that I do not want to add this application, but would also accept a solution that let's me turn off the feature completely. I don't want to add the application to the list because I make heavy use of Multi-Account Containers.