There are two ways to adapt TT-30 to 14-50. One is used for RV, the other is used for EVs.

You have the wrong product.

You want something like (not endorsing this product, just for general information)

https://www.amazon.com/Parkworld-885378-Adapter-TT-30P-14-50R/dp/B07G2MT4T6

1) An EVSE that lets you select 24 amps, 32 amps and 40 amps (40 amps optional if your vehicle can't draw that much)

2) TT-30P to 14-50R conversion cable that is specific for EVs (they also make them for RVs). This will let you draw up to 24 amps at 120v on a TT30 plug.

I am (at this very moment) charging my car with this EVSE on a 14-50R at a campground. We also use this adapter when only a TT-30R. Note that neither of these are UL listed.

I've also looked at this option which is kind of the swiss army knife of chargers. It's super $$$ and I haven't seen any reviews with it.

This one ? And what length? Parkworld 885378 EV Adapter Cord NEMA TT-30P to 14-50R (ONLY for EV or Tesla use, NOT for RV ) (1.5FT) https://www.amazon.com/dp/B07G2MT4T6/ref=cm_sw_r_cp_api_i_HHST24VA75Z9B7H5VZRC