Thank you once again, kemal146. We'd like to help you restore your iPhone to factory settings.
Since anything stored on your iPhone only will be lost when you restore it to factory settings, you can turn on iCloud to keep your information safe:
Set up iCloud Drive -- If you have Pages, Numbers, Keynote, or other documents or spreadsheets, turn on iCloud Drive. This article also explains how to work with your documents after your iPhone is set up again.
Set up and use iCloud Photos -- You can also use iCloud to sync your photos to all of your devices. You can also transfer them to your computer: Transfer photos and videos from your iPhone, iPad, or iPod touch
The same holds true for Contacts, Calendars, Notes and Reminders:
iCloud User Guide -- The iCloud User Guide can provides more information on how each feature works.
Restore your iPhone, iPad, or iPod to factory settings -- Once you're comfortable that everything is syncing through iCloud, use the steps to restore your iPhone to factory settings. Then use the steps in this article to set up your iPhone again. Set up your iPhone, iPad, or iPod touch -- Remember to skip step 2.
Redownload apps, music, movies, TV shows, and books from the App Store, iTunes Store, and Apple Books -- Once the process has finished, this article explains how to redownload your purchases again.
Apple - Support - Product Selection — You can also contact Apple Support to guide you through this process. After selecting this link, type "set" in the Search topics field, and choose "Setting up a new product" in the Results. Then select how you'd like to start the conversation.
Let us know if you have any questions or concerns.
Have a good day!