laravel set a session variable

$value = Session::get('variableSetOnPageA');

// Via a request instance...
$request->session()->put('key', 'value');
 
// Via the global "session" helper...
session(['key' => 'value']);

// Via a request instance...
$request->session()->put('key', 'value');

// Via the global "session" helper...
session(['key' => 'value']);