Should I ground the metal box for 14-50 outlet?

Question

I just finished installing a 14-50 outlet in my garage. I haven't hooked it up to the breaker box yet. I used 6/3 nm-b cable with ground. I made the wire and ground connections to the outlet but I didn't connect the ground wire to the metal box and now I get the feeling that's wrong. Is it? I didn't see a screw on the metal box to clue me in. Should I connect the ground to the metal box?

Here is a picture of the outlet and links to what's behind the plate.

Thanks

Metal box: https://www.homedepot.com/p/RACO-4-in-Raised-Ground-Welded-Square-Electrical-Box-8232/100578083

Metal box cover: https://www.homedepot.com/p/4-in-Square-Box-Cover-for-30-or-50-Amp-Receptacle-Case-of-10-RS13-10R/202597322

Wall plate: https://www.homedepot.com/p/Legrand-Pass-Seymour-2-Gang-1-Power-Outlet-Wall-Plate-Stainless-Steel-SL703CC12/202313808?keyword=785007180268&semanticToken=20030000+++%3E++++st%3A%7B785007180268%7D%3Ast++cn%3A%7B0%3A0%7D++cn%3A%7B0%3A0%7D++785007180268+%7Bproductkey%7D+qu%3A%7B785007180268%7D

Cable clamp: https://www.homedepot.com/p/Halex-3-8-in-Non-Metallic-NM-Twin-Screw-Cable-Clamp-Connectors-5-Pack-20511/100133208?keyword=051411205119&semanticToken=20030000+++%3E++++st%3A%7B051411205119%7D%3Ast++cn%3A%7B0%3A0%7D++cn%3A%7B0%3A0%7D++51411205119+%7Bproductkey%7D+qu%3A%7B51411205119%7D

Answer 1

You want one of these

attached with one of these

right here

Then you can lay the bare ground in the lay in lug, no wire nut in the box, no pigtail ... at least IMO that's the easiest way to ground this.

The green screw is typically used for grounding but you can really use any 10-32 machine screw.

Be sure to choose a lay-in lug that accepts #6 wire.