Not sure. It doesn’t have a brand name on it. This may not be the exact model but it’s looks to be the same one.
Heavy Duty 3 3/8" Centers Chrome Plated Diverter Clawfoot Tub Faucet
https://a.co/d/5LKOtqf
That should be pretty simple to do from tub side.
Tools etc.: phillips screwdriver, flat screwdriver, wrench to remove faucet stem.
Supplies: plumbers grease (waterproof grease) faucet washer (proper size. Sizes are weird: 00, 0, 1/4R, 1/4L. Don't know what you need until you get to it.) Perhaps faucet stem brass screw.
Turn off water. Open faucet so it drains out. Leave faucet open. After water stops, close tub drain. Put a folded towel over it and surrounding tub bottom.
Remove the screw in the handle. Remove handle. May need to pry off. Minerals and corrosion can make it difficult. You will then see the faucet stem.
SOME FAUCET STEMS HAVE LEFT HAND THREADS.! BEWARE OF THIS!
If yours are like the picture, one being left handed is a strong possibility.
Unscrew the brass stem. Deep well socket (plumbers socket) open end wrench, whatever fits and will unscrew the stem from the faucet body. Keep track of any gaskets under the stem.On the bottom of the stem is the faucet washer remove it. There may be a brass screw holding it. Replace washer with new one.
The inside of the stem screws into the outside of the stem. Separate the two parts, grease everything and reassemble. Don't screw in the inner part of the stem all the way.
Put a little grease on the threads at the base of the stem. Screw the stem back into the faucet body. Make it snug but not super tight. There should be splines on the top of the stem. Put a little grease on them. Now screw in the inner part if the stem using the handle (no screw just yet). You may need to reposition the handle a few times) until it is snug.
Remove all the stuff from inside the tub. Turn on water. Tighten stem until water cuts off. Set the handle so it looks like it did when you started. Then reinstall the handle screw.
Repeat for the other side as necessary. Over the next few weeks, the faucet may need to be tightened more. This is normal as the washer goes through breakin. Reset the handle as needed.
Good luck.