@dot.tominator gave a perfect answer
also for anyone wondering: you can always write your own parser in Bluperints using node “parse into array”
in ancient version of UE I made JSON parsing only using this node even with nested structures
you could also use built in plugin for JSON to get basic non-nested fields with arrays and then parse those using “parse into array”
i.e. make your own, can be done in BPs or try to learn basics of C++, which is also the way