Hi I need to know how i can generate the summary of purchasing from a specific supplier ??

Welcome and thanks for visiting the Community today, @marketing6. You can run the Transaction List by Supplier, then customize it to get what you need to show on a report. 

Here's how:

1. Go to the Reports tab, then enter the specific report in the Search bar. 
2. Select the Customize button, then click the Filter option.
3. Check the Transaction Type.
4. Choose the transaction types you'd like from the drop-down menu.
5. Click Run report.

Here's an article for more insights: Customize reports in QuickBooks Online. The article also includes steps on how to memorize a report so you can easily access it again in the future. 

For future reference, you also have the option to export your reports if you need to do some extra work. Here's the article about that: Export reports, lists, and more.

Feel free to comment below if you have any other questions. Wishing you continued business success.