Autologin D8


I’ve developed an autologin by url so that when users click on the link, they are automatically login in my website.
-> I’ve generated a hash based on their email address and i check the generated hash before the website log them.
This works fine and is use in newsletters..

The issue i’m facing is that the system need to be used on partners website to log in users.

– So i’ve developed a webservice and require the email address and the hash as POST parameters.
-> The user is correctly authenticated, but when i go on my website. The user stays anonymous.

Anyone has and idea what’s going on ?

Drupal version: