Look closely at the picture in the link.

Looks like a very small hole at the top of the groove - on the side - in that image.

Two images added just for reference regarding possible location of the feed hole.

A4DA71F1-1550-4016-9DCB-7B010D6D23E5.jpegCFB15410-4D35-4941-B590-A681A0F943DB.jpeg
Last edited by Transman; 02/01/19 10:08 PM.