Sonarr giving error when trying to add Anime manually via interactive search using jackett(Nyaa)

Best guess you have not setup nyaa correctly in Jackett. It is not sending over whatever is tagged as ‘input’ when trying to search. IIRC you need to have anime enabled etc. Don’t use so can’t provide specifics.

See here for troubleshooting https://wiki.servarr.com/sonarr/troubleshooting#searches-indexers-and-trackers

Perhaps think above moving to Prowlarr instead https://wiki.servarr.com/en/prowlarr