According to google, my theme is nonresponsive

To continue this thread over here: https://colorlibsupport.com/t/when-using-theme-on-phone-the-page-is-too-wide-and-has-a-white-part-to-it/#post-252486

The problem with the text on mobile is still there, and google seems to agree.
Apparently, it considers my theme to be nonresponsive and “not mobile-friendly”

What should I do?