What is the best way to design a call to action button for mobile devices?

Question

Design

Good afternoon!
We put a pop-up window on the site so that it calls for action - ask a question, on computers it does not interfere and stands to the right of the site, but in the mobile version it is in the center. How do you think this strip could be designed for phones?
https://yadi.sk/i/o1hP3vVxrxEKe - here is a screenshot of the button

Answer 1

Height 25-30 pixels, change the name to "Ask a question", reduce the width and nail it to the right.

Answer 2

hide when scrolling down, expose when scrolling up - as an option.

Answer 3

It also needs to be made flat. A transparent rectangle with a thin dark outline would still be better for this action.