Washington mentioned THHN or UF for outdoor use. Did he then mean UF can be run in conduit?

I am wanting to put two runs of 12/3 inside conduit running underneath a deck to a hot tub. They are 240V circuits at 20A and 30A. The run is about 50 ft which sounds like 12 ga copper should work.
I saw a 250' roll of 12/3 w/g UF cable that would better suit the project and budget than buying THHN.

Can someone please advise?

Since a spa or hot tub falls under the Code for pools, an insulated equipment ground is required, UF cable is NOT allowed for a spa or hot tub.

Use PVC conduit with THHN/THWN insulated wire.

They are 240V circuits at 20A and 30A. The run is about 50 ft which sounds like 12 ga copper should work.
I saw a 250' roll of 12/3 w/g UF cable that would better suit the project and budget than buying THHN.

Can someone please advise?A) I hope you were not planning on using #12 for a 30A circuit such as this.

B) Why would you have chosen 12/3 for a straight 240v circuit?

C) PLEASE hire an electrician to at the very least help you with this. A hot tub is not a place to figure things out as you go. You should know what you are doing right from the start.

Some may pull 2 #6's a #8 for neutral and a #10 for ground to supply a 4 or 6 circuit panel, install any necessary GFI's, at the required distance.