my phone just won’t update i have the 8 it’s charged and on wifi

For an over-the-air update all of these requirements must be satisfied:

• Charged to over 50%
• Connected to a fast Wi-Fi network
• NOT connected via VPN
• Not in low power mode
• No older update files on the device (Settings/General/iPhone storage: If you see an update file delete it)
• No previous beta version on the phone
• Either plugged in or kept unlocked to keep Wi-Fi on for the download

Try updating using iTunes from your computer instead of over the air.