I checked my manual, It does not say the size. It is a countersink style phillips. The hardware store will have it.Most likley a 8mm. don't get one that is too long or it could hit something inside the drum.

Willie

 

It looks like it is a M8x20 screw, here is a picture so you get the right style head. The manual shows that it is a phillips.
https://www.lrcparts.com/view_produc...e3dd779047e058
Willie