Check if the issues are Hardware or Software
If you have dropped your phone in the pool or on the ground, then the issue might be Hardware. To resolve that, you need to restart your phone, and if it still does not work, go to a repairing shop nearby and let experts do the job for you.
While on the other hand, the issue could be software-related when your iPhone has been affected by malware; it usually happens when you install a corrupt update or malware application. In the software issue case, you canuse thethirdpartytool
Dr.Fone - System Repair (iOS), because it helps the users resolve issues like iPhone Black Screen, iPhone stuck in recovery mode, device stuck in reboot mode, iPhone error 4013, iPhone stuck on apple logo and more.