What does the warning "Cookie will soon be treated as cross-site-cookie" mean in PHP?

The warning "Cookie will soon be treated as cross-site-cookie" means that the browser will soon enforce stricter rules for cookies, treating them as cross-site cookies if they are not properly set. To solve this issue, you need to set the SameSite attribute for your cookies to either "Strict" or "Lax" to ensure they are not treated as cross-site cookies.

// Set the SameSite attribute for all cookies to "Strict"
ini_set('session.cookie_samesite', 'Strict');