Pairing remote to vizio sound bar

how can I pair my direct tv RC73 remote to a Vizio V21-H8 sound bar.  Model is not listed on pairing menu and “I don’t know” doesn’t work.  Two codes and neither works.

Is there a code I can find and manually enter it.

It worked when I first installed the sound bar almost a year ago but replacement remote I can’t get paired.

i don’t remember what I did originally and direct tv customer service can’t help.