Settings - API logs
The API Logs button is only visible if you have MagManager connected with third party account apps.
It works in conjunction with the account apps and displays the interaction of data between MagManager and the third party apps, such as Xero, QuickBooks, Sage, Kashflow & FreeAgent.
Steps to access the API logs
Step 1 - Go to the main Settings page.
Step 2 - Under Settings > Select API Logs.

Each app records different data, below is an example using QuickBooks.

When an invoice does not transfer to the third party accounts app, checking the API Logs will give an indication of what the problem is in the Result column.

Additional links below to error messages specific to each accounts app.
Xero Invoice Transfer Error Messages
Kashflow Invoice Transfer Error Messages
QuickBooks Invoice Transfer Error Messages
Sage Invoice Transfer Error Messages
FreeAgent Invoice Transfer Error Messages

