+1 to the DI recommendations you’ve already received. I always get the best results by capturing both the DI and amp signals, then blending them to suit the song. You can capture the direct sound from the DI to one of the mic inputs on your interface, then run from the DI’s “thru” or “amp” output into your amp, and from the RE20 (killer bass amp mic, btw!) into another input on your interface.
As other have noted, mic placement is super important in getting a good amp tone, as is placement of the amp in the room. Assuming you aren’t in a well treated, acoustically perfect space, you’ll want to make sure the amp is not in a position where you get a room mode that could greatly accentuate a certain frequency and lead to a boomy sound. You may need to experiment by moving the amp around, walking around while playing through it, and listening for any unnaturally boomy frequencies.
Another common pitfall when combining direct + amp sounds is phase alignment. I wouldn’t worry about phase while positioning the mic, as phase relationships can be adjusted manually after the fact in any audio editing software or DAW. Once you’ve captured the amp and DI signals on separate tracks, visually inspect the waveforms to ensure the peaks and valleys between the tracks roughly match up. If they don’t, drag one track backwards or forwards until they do. Try playing the tracks back simultaneously when they are phase aligned, and then when they aren’t - you should hear a significant difference! It’s possible that you could prefer a slightly misaligned phase relationship, which would mask some frequencies and leave others intact, if that suits the song better than a more technically “correct” phase relationship.