How to solve AppStore only connecting to Wi-Fi issue

Re: How to solve AppStore only connecting to Wi-Fi issue

"If you use mobile service to connect to the internet on your iPhone or iPad, make sure that you have mobile data turned on for the app that you're using. To do this, open the Settings app, tap Mobile Data, then turn on Mobile Data."

Above comes from:

What to do: If you can't connect to the App Store, iTunes Store, or other Apple services - Apple Support

(Please see the steps in article if more info. is needed.)