Unable to use iMessage after updating my iPhone

Re: "since update phone wont imessage : It won’t iMessage and one contact it only emails" ,

There are many possible causes for the situation, and we have little info. to go on.

You may want to check whether anything below can help.

✽ Eg: If you have unnecessary third-party (non-Apple) apps installed, such as virus-checkers, ad-blockers, cleaners or the like, (even VPN can cause issues) try turning them off, or uninstall them.

✽ Check any browser extensions installed are up-to-date.

✽ Any third-party apps you find necessary may need updating to remain compatible, and not cause issues.

✽ Check whether your network connection is working correctly.

✽ Restarting an iPhone can sometimes restore order, if something is not working as expected.

✽ Apple support have a trouble-shooting article available (link below):

If you can't send or receive messages on your iPhone or iPad - Apple Support

✽ Messages Support website: (info. / support / contact options etc.) :

Messages for iPhone, iPad, Apple Watch, and Mac - Official Apple Support