Cathie.
re your ZOOM RECORDER
i'm not sure ; but it looks like your zoom recorder has a
usb connector for connection to a pc so it can be used as a recording / playback 2x2 audio interface.
have you ever connected your zoom to the pc via usb ?
is this your zoom recorder ?

https://www.youtube.com/watch?v=LFqo4gOUtgQ

if it IS your zoom in above vid ; the vid shows how to set it to record/playback from pc. which means it might work in realband recording vocals. you can do tons of voc traks in realband. (and also bb)

if its NOT your zoom please post the precise model # of your zoom and confirm that it has a usb port on it.
then the rest of us can look up its features on the zoom
web site.

best oldmuso
ps if zoom dont work i recommend (per upthread) you try a proper audio usb interface.

my songs....mixed for good earbuds...(fyi..my vocs on all songs..)
https://soundcloud.com/alfsongs
(90 songs created useing bb/rb.)