how to loook for niche based directory

hi everyone i need to know what is the best way to search for niche based dierctories

Try googling for term niche + directory.

One of the best sources is to look at other companies or competitors in that space and pull their backlinks with Majestic or Ahrefs and then look for niche directories. The web savvy companies will most likely be in niche directories. Put together a list of the ones you find and go back later to join them. From my experience that's the best way because they have been harder to find than I expected.