Fiery Feeds action?

I have an idea for an action to grab RSS feed from an instagram feed and subscribe to it via Fiery Feeds new x-callback but I’m clueless as to how to make it!

1: copy the Instagram url eg

2: strip away all but the username and insert that into the url

3: this uses RSS Bridge to create an RSS feed for that user

4: put the resulting url into Fiery using their x-callback - fiery://x-callback-url/subscribe?x-source=app&url=&x-success=sourceapp://x-callback-url/success

The <> need stripped out

Can anyone help with this?