Introducing "Request sign-off" - an approval flow that requires no set up

My users have 'edit' permission and it still doesn't work. For one user there was a box about sharepoint permission issues but nothing to click or otherwise update. For another user, I had to go to flow.microsoft.com and click 'my flows' to assign correct permissions to sharepoint for them. Both of these users had full edit rights on the document library prior to starting the flow and the document wasn't checked out to anyone. Seems that there are still some permissions issues to be solved. Users shouldn't have to know about 'flow.microsoft.com' in order to use this.