break this up into two queries:
without_term_id=12term_id=12&term_value_id=13
who knows exactly what’s intended except for the person who wrote the code?
when you use term_id_or_unknown + term_value_id, you will get only observations that have your term_id + term_value_id or observations with some other term_id.
when you use term_id_or_unknown + without_term_value_id, you will get observations with no term_id or any annotated observation without your term_id + term_value_id.
…
there’s some related discussion here: https://forum.inaturalist.org/t/identify-filter-without-annotation-not-working-properly/30148/18