Do you mean a

window.alert('Some text');

dialog?

You can press Ctrl+c to copy the selected text.

I don't think there are any other applicable actions that would appear on a menu. What did you have in mind?

Your Firefox identified itself as version 81, while the current release is version 87. Are you holding off on updating for a specific reason?

I mean <input type="button" onclick="alert()"> And, yes Ctrl+C is working. But I am missing the right click menu in FireFox.

I am missing the right click menu in FireFox.

Agreed, there is no right-click context menu. However, the only thing I can think of that would be applicable from the menu is Copy, and maybe Select All.

There are keyboard shortcuts for those, so I suspect enabling a menu would be a low priority (that's a guess, it's not my decision).

What the dialog needs is a button like "Close this tab, I'm annoyed by all these alerts" but I'm not sure that would fit. ;-)

Yes, for the Copy. I often use a website which shares information via Alert Dialog which I need to copy and use in another application. And it is (would be) much more convinient and faster in my case if I had right click menu (then double/triple clicking to select text and) Copy because I would need one hand only for this task, while I could prepare my other hand to press Alt+Tab to switch to the other application (without repositioning hand/fingers from Ctrl+C). Thank you for your comments anyway!

Each site might be different, but Ctrl+A Ctrl+C works for me, which is not too bad. Of course, this could by why my wrists and arms hurt so much lately!

How can I submit a suggession to the developers? Maybe they consider implement it. I cannot be the only one who is missing this option.

You have many choices to submit feature suggestions, depending on your desired style of interaction:

Discussion Sites/Advocacy

• Mozilla Discourse: https://discourse.mozilla.org/
  If none of the categories seem to fit, try https://discourse.mozilla.org/c/firefox-development
• Reddit (monitored by Mozilla): https://www.reddit.com/r/firefox/
• Twitter (Mozilla official): https://twitter.com/firefox

Bug Tracking System

• Unfortunately, new feature requests tend to get a low priority: https://bugzilla.mozilla.org/
• See: Bugzilla Etiquette