Based on code from the site https://www.cyberforum.ru/csharp-beginners/thread2787671.html
I refactored the code, converted everything to Vector2 and float, and supported negative coordinates.
Installation as a unity module via a git link in PackageManager or direct editing of `Packages/manifest' is supported.json:
"com.elmortem.delone": "https://github.com/elmortem/triangulation-delone.git?path=Packages/triangulation-delone",
Thanks Woldemar89 and cergeq.