Use the Quick Settings menu and tap Restart if available
Plug the phone into a charger and wait for it to wake up
Use the Accessibility menu and select Restart if enabled
Schedule an automatic restart in the phone settings if supported
Use a connected computer and device management software to reboot the phone
Remove and reinsert the battery if the phone has a removable battery
Let the battery drain completely, then charge it to power it back on
Use a hardware key combination if your phone model supports it
Ask a service center to replace or repair the power button