Error in cUrl for Qualtrics File Service

Hi,
I´m trying to upload the cUrl for an automation, using Qualtrics file service.
I´m using this
curl -X POST -H "X-API-TOKEN: cqnf9cDcsjc0aHposQgGGXySWfOvd1PZ1kkir4ZV" -F 'file=C:/Temp/Padron.txt' https://yul1.qualtrics.com/automations-file-service/automations/AU_0HKSv9dPdbMbZkj/files
But the answer shows me an error:
{"meta":{"httpStatus":"400 - Bad Request","message":"missing form field 'file'","requestId":"4ff1ed28-15e8-4211-96b8-71ae032b8a12","transactionId":"a0d341c3-1631-4d0c-8e70-e181a6a078d9"}}
Does anybody know why is this happening?

Thank you !!