I have created a PowerApp which generates a CSV file for adding tasks on Azure DevOps. It takes user-input information to the PowerApps Collection, and then sends it to a Flow which converts it to a JSON and then creates a CSV file which is saved locally through "Create a file OneDrive Business". It works flawlessly for me, but when I had a user test it they got the error:

I have shared the PowerApp with the user, so I'm a bit stumped as why they are being denied access. I read that Flows triggered by PowerApps aren't required (and can't) have a list of allowed Run-Only users.