"GET / HTTP/1.1" 404

[lostNG]

message with

I am Coffeebot ::robot_face::, and I'm here to help bring you fresh coffee :coffee:

shows up in channel, but nothing happens then.
Terminal and ngrok display:

GET /                          404 NOT FOUND                                                      
GET /favicon.ico               404 NOT FOUND   
GET /slack/message_actions     405 METHOD NOT ALLOWED

[lostNG]

message_action and button work now but no loading forever (guess related to the 404)