this topic has been previously discussed many times in the forum.
this thread may be useful to read: https://forum.inaturalist.org/t/using-the-field-similar-observation-set-for-linking-observations-of-lepidoptera-when-raising-on/1018.
also, look at the list of related threads at the bottom of the first post in that thread. some of those address your exact question. here’s one of them, just for example: https://forum.inaturalist.org/t/repeat-observations-same-individual-how-to-submit/4252.