this can give you observation counts in a table for all countries defined in iNaturalist:
https://jumear.github.io/stirfry/iNat_countries?user_id=danielaustin&stats=observations (atthough there’s a known issue with Taiwan). you can also get species and other stats by modifying the URL. there are instructions at the top of the page.
if you’re not sure how to use this data to make a choropleth yourself using some code or in a tool like Excel, you can try using an online website like https://www.datawrapper.de to make one. either way, you may have to reconcile some differences between what iNat considers a country with your country polygon source.
i don’t think this is generally possible in all cases, since i don’t think you can get rankings beyond 500 nowadays. you could get this data yourself anyway, but because of the limitation, i’m not going to make a tool to get this information.