It says an update is required to use cellular data my phone has been updated and still won’t work

Are you asking about an iOS update or an update from your carrier?

If a cellular or carrier update is available, it will usually be displayed at......

Settings > General > About

You may need to contact your carrier for more information.

The issues in this support article appear to be your situation.

If you see a Cellular, Ultra Wideband, or Apple Pay Issue message after an iOS update or restart - Apple Support

This may apply, but the "free fix" is long gone.

iPhone 7 Repair Program for "No Service" IssuesAppleOfficial Apple Support › iphone-7-no-service

Same and I contacted support , issue still isn’t fixed, I have an iPhone 7…I refuse to pay a ton to get a new phone.