There are a number of reasons that this may have happened. This solution outlines one of them. Note, it only applies to Audit Trail installed on Azure.
Open up the Azure portal by going to https://port.azure.com
Look for or search for the function app resource for Audit Trail. It will begin with fa-at... It will look something like:
Go to that resource page. Ours is shown below:
Copy and paste the URL value into a browser. If nothing appears after a very short while or you get
Then you may want to restart the function app.
You can do that by pressing the Restart button on the page above.
Try the website URL again and you should get the following:
