Automating the Posting of A Collection of 1..M Payloads Pre-Prepared as JSON files

*I have a number of .json files representing the payload to be posted, each payload has a few hundred to a few thousand JSON objects. Can I get Postman to “post all the files one at a time” and wait for a response between each? *:

I’ve read about using CSV files to substitute for parameters but in this case I simply want to post a big JSON document (1 payload per json file) to the same URL in serial. The variability is in the batches of files (I may have one file 20, or 50 to process per batch).

Content Sample for each File
{
“MembershipRecords”: [
{“MemberKey”:“352842”,“ContractNumber”:“LP17099541838U”},
{“MemberKey”:“352843”,“ContractNumber”:“LP17099541999U”},

… several thousand lines…
]
}