Example
Save the session variable as a variable.
$session = Yii::$app->session;
$sess = $session['keys'];
Then create or update the array value you want
$sess['first'] = 'abc';
And finally save to the session variable
$session['keys'] = $sess
Save the session variable as a variable.
$session = Yii::$app->session;
$sess = $session['keys'];
Then create or update the array value you want
$sess['first'] = 'abc';
And finally save to the session variable
$session['keys'] = $sess
