curl --request POST \
  --url https://api.app.lastaccountingcompany.com/portal/uploads \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form 'files=<string>' \
  --form 'customer_id=<string>' \
  --form 'message=<string>' \
  --form 'submission_id=<string>' \
  --form source=portal

{}