Program logic run in flow but not webhook

hi gurus,

i have my flow tested that could pull from source and push to target application, screenshot #1 (both via API, credential set under environment), but once i deployed it to webhook (screenshot #2) and run it by hit send button, it only response (screenshot #3) with following json and doesn’t perform the sync

“event”: “64b7480c7b1075ac8c0d2de7”,
“timestamp”: 1689733132594,
“state”: “processing”,
“message”: “A flow run has started for this webhook call”

this is the detail of my flow, which executed via webhook

here the detail log, it shows that the token for my target environment is captured, and the source are pulled successfully. How come it doesn’t execute the for loop and perform the import?

thanks for the pointer