In general, the adverbs puis and ensuite are synonymous. However, puis is typically used as a conjunction and cannot be placed at the end of a sentence whereas ensuite can be placed anywhere in a sentence
qu'est-ce qu'il a fait ensuite? - what did he do then?
This sentence cannot be translated as: qu'est-ce qu'il a fait puis.
These sentences lack context (unavoidable) but there are often a number of possible interpretations. Here I translated "place" as parking spot" which in many contexts is correct. Here I can see that Duolingo hasn't included it in their list of answers but many times it is frustrating and the sentences seem incredibly stilted without context