In other games I open up the keybindings to check. Battlefield, Battlefront, Hero’s & Generals, Hell Let Loose, all different. I don’t don’t remain totally helpless.
google...
Battlefield V: Default Chat Enter
Battlefront 2: Enter Chat / send a message
Hero’s & Generals: Chat Return
Hell Let Loose: Chat All Return (could only find it in an in-game screen-shot, no tutorial or anything).
Yes, there is additional special buttons for team/party chat, but Enter/Return opens a chat in all of those games you listed.