Hello,
its not possible to "install" on the fly.
Have a look at these informations for understanding:
https://github.com/recalbox/recalbox-os/wiki/recalboxOS-detailed-%28EN%29
https://github.com/recalbox/recalbox-os/wiki/Compilation-and-Modifications-%28EN%29
https://github.com/recalbox/recalbox-os/wiki/Recalbox-development---basics-%28EN%29
And dont make crossposts:
https://forum.recalbox.com/topic/13134/sheepshaver-basilisk-ii