Download secure attachments from confiforms

[Peter]

I built a confiforms app where users can upload documents. To retrieve these, I query the data via the REST API and get the following content: 
{
"total": 1, "list": {
"entry": [
{
"recordId": 121,
"createdBy": "heusch",
"created": 1755163242079,
"id": "18f26577-15e6-4023-8745-1c2302f7c39a",
"fields": {
"Fakultaet": "C",
"Email": "peter.heusch@hft-stuttgart.de",
"Matrikelnummer": 123456,
"Fullname": "Peter Heusch",
"FakultaetTest": "C",
"StudiengangFakC": "e25f9f73-d783-4aca-8cdb-57732c785d75",
"Praesentation": false,
"Nachname": "heusch",
"Studiengang": "Bachelor Informatik",
"Auslandssemester": false,
"BPSStatus": "default",
"Stellenbeschreibung": "[{\"fileName\":\"merkblatt.pdf\",\"id\":\"150409792\",\"contentType\":\"application/pdf\",\"version\":\"1\"}]"
},"ownedBy": "heusch"}]}}

However, to download the attachment "merkblatt.pdf", the URL is https://wiki.hft-stuttgart.de/download/attachments/150409791/merkblatt.pdf?version=1&modificationDate=1755163242128&api=v2, which is off by one. How do I get from 150409792 to  150409791? 
Any help greatly appreciated

[John Funk]

Hi Peter - Welcome to the Atlassian Community!

It's best to contact the vendor directly to get assistance. 

@Alex Medved _ConfiForms_