PHP session

Wp and the hoster swear at the php session. It is clear that wp does not use sessions.

Wp error: The PHP session was created by calling the session_start () function. This prevents REST API and loopback requests from working. The session must be closed with the session_write_close () function before making any HTTP requests

I use are child theme. If i add this cod in function.php my child theme:

add_action('init', 'start_session', 1);

function start_session() {
if(!session_id()) {
session_start();
}

add_action(‘wp_logout’, ‘end_session’);
add_action(‘wp_login’, ‘end_session’);
add_action(‘end_session_action’, ‘end_session’);

function end_session() {
session_destroy ();
}

This action don’t work. I think becase need to add a global variable yes?

This is.
$foo = ‘Foo Data’;
$_SESSION[‘foo’] = $foo;

But i dont now when file i need rhis global variable.