How To Prevent Enter Key From Sending Chat Message

What do you mean by format mode?
Are you talking within the context of Windows?
Even the question doesn't seem to explain the context.
Are we talking about web apps running within a browser?
If that is the case, then change should be easy to implement by the developer an₫ be part of the settings:
In cross platform javascript an "on_event" function can detect the key pressed from then on it is a simple if then statement.
I really don't understand why the site owners & developers make such a big deal out of it.
I wrote an extension for Youtube that does the same sort of thing. The same can be don't for apps like WhatsApp.

My question is WHY it isn't?
It is a real pain in Open AI's chatGPT relevant portals. It is ridiculous. There must be a reason for it. In fact, Co-pilote on the sidebar of Edge has Enters as line feed as default which should be the case for all chat boxes.

Now you are referring to format mode that I am intrigued about. So, can you please give me details.

I might be able to change it using programming, but I don't have the time, and it shouldn't be me but the site owner and the responsible developers to do it.

This is something pointed out by someone. You might have already responded to it, but I came across your first response from someone who has managed to do it. Therefore, I apologise, and I would be grateful at least send me a link to your previous explanations, if any.

Thanks

Thank you! Your simple response was spot on!

This portion of my example script:

#HotIf WinActive("ahk_exe ms-teams.exe")

will limit this hotkey to ONLY swap the keymapping within teams.

This portion of my example script:

#HotIf WinActive("ahk_exe ms-teams.exe")

will limit this hotkey to ONLY swap the keymapping within teams.

I had independently tried an AutoHotKey fix to map shift+enter to enter and vice versa. I threw it away because I couldn't find a way to make the script understand the format vs normal mode. Swapping the keys just swaps the mode in which the accidental sends happen, and it turns out I use both.
If there is to be an keyboard shortcut for something that isn't related to entering text, it needs to be constant through editing modes. An exception for letters and caps lock, but if I miss that mode toggle then I'm only shouting and that I can edit before the message is sent out.

Funny thing, in this text entry box, enter does as enter should even before I click a format function.

You might try mapping enter to shift-enter, and mapping shift-enter to ctrl-enter.
If you hit ctrl-enter, it sends from either mode, and shift-enter enters a newline in either mode. There might be a combo that gets you the behavior you want.