YouTube Studio hashtags for channel profile.

From YT Studio Dashboard choose ‘settings’

Add hashtags from saved #htmusic google doc.

(more on that later)

Also add hashtags to upload defaults  (scroll down to see the Tags option)

Interesting link about #hashtags

#teachorbetaught

UPDATE:  Using too many may affect your results.  This article suggests that 15 is the most you should use and provides more advice about using hashtags on #youtube