You can try waniconjugation.herokuapp.com
Basically, you put in your WK API and it tests you on verbs (and adjectives) that you’ve learned on WK. You can test stuff from a specific level, or everything up to your current level.
Welcome to ‘WaniConjugation’, a site for Japanese language learners to practice conjugating verbs and adjectives. This collection of 955 verbs and 580 adjectives, their meanings, and their ‘levels’ originates from the Great Crabigator over at WaniKani. As such, this tool is optimized for users of that site. If you’re not already a member and are trying to learn Japanese kanji, what are you waiting for? Go sign up!