While downloading expense reports is not currently supported out of the box, you can work around this issue and download an expense report based on its ID.
First, you need to export and download the export file:
In the Payhawk portal, go to Export.
Export your expenses for the desired period. The export file that was downloaded on your device will contain the Expense report ID column.
Then, filter out the desired expense report based on its ID and download it:
Go to Expenses.
Filter by Expense report ID.
Click on Download.