I have read where many travelers get help from airlines and hotels by using Twitter to tweet messages to the airline or hotel asking for assistance. I just created a Twitter account but I'm having difficulty understanding how to respond when an airline or hotel asks me for more info. I see there is a "reply" button, but when I read others tweets the airline says to DM the details to them. I don't understand how I can DM them back (vs. just replying)- I see no button to do that. Can anyone give me some guidance?

Thanks.