Uploading a file to an order

Hello, I'm trying to transfer a file via API request, I was looking for how to do it and found an interesting answer on the forum - https://1b.app/ru/forum/api-onebox/12801-polucheniya-fayla-iz-1s-v-zakaz/ and I made a test script, but I must have written something wrong, because it gives an error. Tell me what the problem could be? And perhaps this request can be made on API v2, since it seems like API v1 has already removed the documentation and we need to switch to more up-to-date methods. [file]23578[/file] [file]23579[/file] [file]23578[/file] [file]23579[/file] [file]23578[/file] [file]23579[/file]