I want to add bootstrap to my project and didn't found Client-side library on options
The Library Manager feature (Add Client-side Library) is not supported on VS Mac. You can request it, and if it gets enough votes the team might consider it a priority to port to Mac.
There is also an older port (i.e. not the latest, not officially supported, may have bugs/issues) of it here (blog post by the fork author from 2019).
