Course creation: Want to update an issue, but the bot is the owner

Right, so I want to make use of milestones and assign issues to different milestones using the octokit type action, but since Im not the owner I am not allowed to update it.

We have tried 2 things:

1) action type octokit method issues.update
Returns an unexpected error. I think its auth related since Im not the owner of the issue, the bot is.

2) action type octokit method issues.create
This works fine and I can assign it to a milestone, BUT I cant use a markdown file for body. And this is much needed since some of our issue-bodies are quite large.

Anyone see any neat ways around this?

Cheers, and keep being awesome.