I’m trying to do an update, but it’s satin not connected to the internet which isn’t true. What’s going on. My iPhone 12 Pro Max isn’t letting me receive messages.

To update over the air from the phone all of these requirements must be met:

• You need at least 6 GB of free storage; more is better
• You must be connected to a Wi-Fi network (and not a personal hotspot) unless it is an iPhone 12 or later with an active 5G network connection
• The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
• The phone must not be in Low Power Mode
• The phone must not be connected through VPN, and it may be necessary to delete any VPN apps and VPN profiles
• The phone cannot be in Airplane mode
• You cannot still have a beta version installed on the phone
• You cannot have a previous version that was downloaded, but not installed - go to Settings/General/iPhone Storage to look; if you find an iOS installer, delete it

If you can't meet all of them you can still update using your computer.