Where to Find and Catch Tapu Fini
From Pokemon Go Wiki
Tapu Fini are found and captured in Nest and Habitat locations.
Nests
Tapu Fini Nests are locations that consistently spawn Tapu Fini.
Habitats
Tapu Fini Habitats are spawn locations where Tapu Fini is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: