How to make 10 digit number validation JS, HTML?

Question

JavaScript

Good day, tell me how you can validate a phone number in a 10-digit format, without 8 and +7.
That is, the user enters +7ХХХХХХХХХ or 8ХХХХХХХХХ, then it will give an error message.
At the same time, there are numbers whose operator code can be 800, 804, etc. (toll free numbers), that is, they start with 8

Answer 1

You can just google