Reporting - Total Volume by Customer (Monthly) - All SKUs

Hello, as per title.
Could you advise as to how to pull a report with these metrics?
We offer a volume retro for our customers over total liquid volume purchased monthly, so we don’t need to see individual SKUs, just a total volume of liquid over a set time period. Please advise, thanks.

Welcome to the Breww Community!
Sure. Go to Reporting > Aggregate report builder > Products sold (order lines). Change your first metric to volume, then your first metric extra grouping to customer.
That should give you what you need! It might be easier to click the button at the top to view it as a table, or to export it to Excel.