https://wccftech.com/new-fallout-76-mod-text-chat/

Being an online-only game, Fallout 76 is all about interacting with other players in a variety of ways. Many have been asking Bethesda to implement more ways to communicate with others other than proximity voice chat, but the developer has yet to introduce them. Thankfully, a modder managed to introduce a new way to talk with others for the PC version of the game.

The Proximity Text Chat Fallout 76 mod introduces the ability to text chat with other players who are within 100m.