Convert SQL Query to Laravel Query - Laravel 7

I have query

SELECT * FROM visitors WHERE created_at > DATE_SUB(NOW(), INTERVAL 1 WEEK);

It worked perfect.I'm trying to convert it to Laravel query

$visitors = DB::table('visitors')->select(DB::raw('*'))
            ->whereRaw('created_at > DATE_SUB(NOW(), INTERVAL 1 WEEK')->get();

I kept getting error

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1 (SQL: select * from visitors where created_at > DATE_SUB(NOW() = INTERVAL 1 WEEK)

Can someone help ?

via Chebli Mohamed