Hey @david.brnovjak
thx for the feedback.
The Adding a File via Pipedrive API documentation at step 7. Full working example (Node.js) should be updated. There the parameters are with underscores.
Additionally we found the solution for using fetch: don’t set the content type explicitly. We removed
headers: {
"Content-Type": "multipart/form-data",
},
and the upload works fine in our application via the API