How to synchronize cookie data across different domains?

Question

HTTP Cookies

Hello, I have a problem. It is necessary that in the calculators the amount on the domain.ru and account.domain.ru domains be the same when changing the amount. Those. synchronized. For example, I will change it to domain.ru for the amount of 200 and on another domain it also changed to 200.
Is it possible to implement this through cookies?
If not, how can this be done?
It is desirable to implement this through js.

Answer 1

Cookies for another domain cannot be set, nor can they be read. Forbidden by security policy. There are all sorts of tricky options like background tabs and passing cookies through get requests, but these are the wildest crutches.
I would do so. I would receive the fingerprint of the system, and send it and the desired value to another domain, where it would save / update it in the database. When a user visits a domain, he would receive fingerprint data from the database and substitute it.