facebook messenger, link button

I have a comment that needs your updates.
when my customers visit my website on mobile and they want to chat with me via facebook messenger. then the facebook messenger button takes them through another fb browser tab and asks them to login. I want the facebook messenger button to switch to the facebook messenger app, not another login tab on the browser. FB instructed me to insert the link form https://m.me/*** to open the mess FB application but this type of link is not supported by chaty. Will you update this issue?

And there’s another problem: I need 2 links for some purposes, but now I can only create one link path button.