Over the years I have always used the same method.
Input the chords in BIAB. Get a decent version of the backing tracks.
Render the tracks individually into .wav files.
Open Reaper, import the .wav tracks and work with them there.

So I was looking at the top left of the BIAB screen and trying to see which button to press to start this process.

I saw the DAW pluggin button and pressed it but nothing special happened.
So I watched a YouTube video on the BIAB plugin and followed along with Reaper.

I must say I was left scratching my head.
Why in the world would I want to install a BIAB plugin inside Reaper so that I can start Reaper and create BIAB tracks inside Repear????

Huh?
BIAB is dripping with 1000's of features.
Does it make any sense to create BIAB tracks inside Reaper when I obviously will lose
most of the BIAB features in doing so?

What is the whole point of this BIAB plugin?
What am I missing?

How difficult is it to do what I just did and have always done?
Create the tracks in BIAB and then import them into your DAW?

A BIAB user for more than 30 years (if you can believe it) !