You notice the Flex datasource is not processing the Prisma JSON file. It shows the Processed, In Queue, Failed are all 0 B, but the file is sent to the Datasource.
If you try open the file using notepad and found you cannot read the file, and the file contains "compression":"snappy" as shown below:
Then this file is compressed by snappy, which is unreadable by the Datasource processor. You will need to first try export the datasource file without the snappy compression.