checkbox teacher calendar -- 2

users can set multiple time slots in day and when he uncheck the checkbox we need to set it to unavailable and when he check that checkbox again we need to set it to old values
good example
https://drive.google.com/file/d/1q49plEkgPc7XtDkGib6N2nOXT-CtxFq2/view?usp=sharing
bad example - our current
https://drive.google.com/file/d/1G7FM3B-Gu8uIcx2Hval7ArQfx0ERSPFC/view?usp=sharing
link to Git - access for code
https://github.com/haseebibrar/uptick-new

user: teacher2atuptick.com
pass: 123456