kerkenat,
I've just tried it out.
Since you have already entered your repeats, the best way to do what you want is to expand the view so that the repeats and DS will show as greyed out areas in a linear view. To do this, (1) click the FakeSheet button and (2) remove the check mark from the top option I've highlighted on the image below.

Once you can see the greyed out regions (bars 9 to 16 on the below image are the repeat of bars 1 to 8), you can then click on the bars in those regions and go into notation editor to add note-based lyrics. Everything will be exactly the same as what you've used to with note-based lyrics.

BIAB treats repeats and DC, DS as a linear performance, when the above 'FakeSheet' option is set to active, it condenses the view of both the chord sheet and the lead sheet. This is purely cosmetic. Behind the scenes, BIAB is still playing in a linear fashion. It is the 'FakeSheet' button highlighted above toggles between the condensed and linear view.
Once you've completed what you need to do, simply click on the 'FakeSheet' button, activate the top option and the condensed view will return.
Regards,
Noel