How to create a Custom report to find the sales of an item

I’m trying to create a custom report where I can list sales of a specific item per month.

See the following image, I sold this blouse and in the description it says GLM, how can I create a report that tells me all the items sold in a month with the brand GLM

Forum rules require that when you ask questions about custom reports, you post your best attempt at creating the report you want. Then show the results and explain how or why it does not fit your needs.

That is part of a Sales Invoice

Have you looked at the Sales Invoice Totals by Item report, where you can drill down on a specific inventory item and also specify the date range. To get what you said you want, you don’t need a custom report.