De-virus iPhone 13

Just because Google might say something does not mean that it is true.

Your phone does not have a virus.

Chances are, the message is not from Google at all.....but from someone else who is trying to trick you into believing that it is from Google

It's a scam. Ignore the message unless you want to buy useless software that will do nothing to help your phone.

Can you recommend any good way to to be sure

Never provide your Apple ID and Password to anyone.

Never click on a link in an email or message.

For example.....you see a message from your "bank" (or at least it looks like it is from your bank) that says that they have detected "suspicious activity" on your account and your account will be frozen unless you click on the link (to provide personal information to the scammers).

Don't click the link. Instead, log on to your account at the bank directly....and guess what?.....nothing is wrong.