Hi @jon welcome to the forum.
iNat does have the ability to upload observations via csv. There are numerous threads on the forum about this that you can check out, examples:
https://forum.inaturalist.org/t/bulk-upload-of-observations-metadata-to-inat-from-excel/13292
https://forum.inaturalist.org/t/specification-for-csv-upload-file/42366
https://forum.inaturalist.org/t/import-via-csv-can-this-include-additional-observation-fields/13013
That said, iNat does have a ban on machine generated content. There’s not a lot of detail in your post, so I can’t be sure, but a program that creates IDs for recordings without human input for upload would likely qualify as machine-generated content:
https://forum.inaturalist.org/t/community-guidelines-update-re-machine-generated-content/29029
https://www.inaturalist.org/pages/community+guidelines
One other thought is that, if the observations are already added to eBird, adding them to iNat as well may not be needed.