Cannot Post listing to server

Using the code provided by Mosh, I cannot post the Listing form
The course is React Native Advanced - Networking

SyntaxError: Unexpected token 'n', "#" is not valid JSON
    at JSON.parse (<anonymous>)
    at createStrictSyntaxError (/Users/davidetamagnini/Downloads/Backend/node_modules/body-parser/lib/types/json.js:158:10)
    at parse (/Users/davidetamagnini/Downloads/Backend/node_modules/body-parser/lib/types/json.js:83:15)
    at /Users/davidetamagnini/Downloads/Backend/node_modules/body-parser/lib/read.js:121:18
    at invokeCallback (/Users/davidetamagnini/Downloads/Backend/node_modules/raw-body/index.js:224:16)
    at done (/Users/davidetamagnini/Downloads/Backend/node_modules/raw-body/index.js:213:7)
    at IncomingMessage.onEnd (/Users/davidetamagnini/Downloads/Backend/node_modules/raw-body/index.js:273:7)
    at IncomingMessage.emit (node:events:519:28)
    at endReadableNT (node:internal/streams/readable:1696:12)
    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

This is the error i get, I can see the data at the current IP:9000/api/listings.
Any help?