Hello. If you have mywebsitename.com linked to mywebsitename.000webhostapp.com (see this topic) then you won’t face problems (described below). But you can change the address only if you have mywebsitename.com linked to mywebsitename.000webhostapp.com
Generally speaking, changing Wordpress URLs won’t affect the functionality of the site; but I can’t speak in the name of Wordpress plugins…
I advise you setup both URLs to the same address, so you won’t have to deal with CORS or Blocked Mixed Content issues