I bought both. The adapter didn't come in time from Tesla before my trip. The 14-50 to 10-30 came in 2 days from Amazon. I kept the Amazon one and gave the adapter from Tesla to a friend.

This is what I got FROM Amazon. Works fine. SetWire NEMA 10-30P to 14-50R EV... https://www.amazon.com/dp/B0BLYNWD24?ref=ppx_pop_mob_ap_share