I cant send messages on my xbox account

Ok I need some help, I cant send messages on Xbox, I don't have an Xbox but I play on windows ten and when I try to put my phone number in the bar to send a code to my mobile on support to fix my problem, it does not send and I have tried multiple time
and I even made a new account (this one) and I thought it was all good now but now I still cant send messages and it is super annoying. I can get messages but I can respond, I can friend players and all of that is fine besides messaging. so I get all these
messages and I feel like the people who messages me think I don't care and I do but I cant do anything about it and I would really like your help Xbox support or anyone who could help me out. Thank you.

:)