I recommend, as do many on theis forum that you build out the song in linear form - first bar to last bar - with all lyrics in place. There are no repeats at this point. SAVE THE SONG
Once you have the song playing as you want, use the repeats / endings dialogue to create the fake sheet. Make sure you uncheck the generate Insert (new) bars as you don't need them since your song is already complete

Remember that this is a "print" function and doesn't affect the way the song plays. This is controlled by your saved song. If it the printed output doesn't quite work, go back to the repeats dialogue and "Edit List" and fix the problem. This is generally caused by incorrectly assigning start and end bars.

You can create loops within loops, DS etc. These are all part of the printed fake sheet. The underlying song has not changed.

There are some quirks as this part of BIAB hasn't been fixed for years.

SAVE THE SONG WITH A NEW NAME

I have songs with 4 lines of lyrics. If the lyrics are the same in 2 verses in the same bars generally you will only see one line of lyrics - BIAB just hides identical line of lyrics.

I only use note lyrics, so I can't comment on how bar lyrics will work

BIAB for Windows Version 2019 (643)
Windows 10 (1909)