Unable to POST .rpm file using InvokeHTTP processor - NiFi

Hello, I have been tasked with POSTing a .rpm file (RedHat package manager) to a server location, this is to automate a manual process that we perform on a weekly basis.

I am able to download the file into NiFi using InvokeHTTP GET. At this stage the 'Content-Type' attribute shows as 'audio/x-pn-realaudio-plugin' , I have read online that this is a common mistake when dealing with .rpm files. I have then used a IdentifyMimeType processor which updates mime type to: application/x-rpm.

In the API documentation is says I require POST /rest/v1/updates as location 'file' as a parameter, see below:

I have been given the following python script that achieves what I am trying to do in Python, so far I have not been able to replicate in Nifi.

I have tried numerous different configs of the processor, manually changed attributes: file, filename, mime.extension, mime.type, Content-Type, Accept-Encoding. I have tried manually adding attributes from the Python script and referencing from the invoke. I have tried to compress to gzip as I was informed it should be in compressed format so I though NiFi had maybe changed it.

So far I have never had anything other than 'no retry' responses.

I currently have set up my invokeHTTP as below:

When I have 'Send Message Body' true - I get the following response:

When I set 'Send Message Body' false - I get:

Any assistance with this at all would be v.much appreciated. I have been trying for a number of days with every different option/config I can think of but cannot get it to POST.

In the script if mentions getting a 'csrftoken' response, am I able to do this using another invokeHTTP?

Thanks in advance

Griggsy