I moved this from Feature Requests to General since it wasn’t about adding new functionality and didn’t include the Feature Requests template.
Greenlandic is currently available as a lexicon on iNat, so I don’t think that there is a need to add it for common names. Info on adding lexicons can be found in this thread (https://forum.inaturalist.org/t/how-to-create-lexicons/18195) though that doesn’t need to be done for Greenlandic.
If the question above is about the iNat site/platform itself being in Greenlandic, translation of iNat is done via CrowdIn (info: https://forum.inaturalist.org/t/introduction-to-translation-with-crowdin/23890) It looks like Greenlandic is available on CrowdIn, so you could help by doing any needed translation there.