Q: I have read all the steps for how to fix issue that my iPhone is unable to connect to iTunes Store but still nothing worked if you know any

Firat of all , I would appreciate yours reply . then in above where you tries to know more about issue as if what type of error comes . Ok when I straight up to go to App Store and iTunes I recieve pop up to sign in given apple account and after filling it , I again get the pop up  . My issue is not limited to just pop up inside settings where I tries to fill passw again and again . Nothing works but a message appears unable to connect to iTunes Store. this issue is incurring from last 2 days . when the first time when I got this issue I was unable to download and update any app . Then my next move was to sign out . then I tried to sign in using App Store and iTunes in settings what actually happened when I fill in account id and password the sign in button turns grey then comes out with blue . Then what I did even you talked about restarting device your device , yes I did in hope to get the issue fixed but it didn't work . The next thing what I did is connecting to iTunes on windows and sync my phone and logged in apple ID and purchased apps. I went to see preferences and parental control if it would work . it actually did nothing but it auto filled on my iphone Apple ID but when I tries to download any app it doesnt download it shows the above error . You even talked about if I did reset then no , I didnt  if it could force me to download latest version