How to switch slots without a computer or using TWRP?

I'm working with Android 9 Pie and I have one slot rooted (slot A) and the other is not (slot B). My reasoning to have my phone this way is because I need the non-rooted side to log in to the app I use for my job. (Even though it still works if I log in on slot B and then switch slots via TWRP without logging out). I've tried the outdated [Switch My Slot](https://github.com/gibcheesepuffs/Switch-My-Slot-Android) app which crashes immediately. I'm mostly looking for a command I can run via termux to speed things up as opposed to just switching slots in TWRP which takes longer than just a command that would switch slots and reboot. How to switch slots without a computer or using TWRP?