If you are trying to access a PowerApps form and you are given a screen that looks like this:
This means this specific PowerApps form needs explicit permission to use your SharePoint Profile.
Verify that your Sharepoint email address is your IWU email address, then select "Allow". The form should then load.
You should not be prompted once to allow access to the form. After approving the first time, it shouldn't prompt you again.
If you select "Don't Allow" the form will not work correctly.
-If you have selected Don't Allow by mistake, try clearing your web browser's cache and try again.