I'd like to export my invoice to excel template for quickly made purchase orders for my installers

Hello, and welcome to the Community, jim99.

I'll help you with exporting this data. The steps aren't too complicated, so once you've done it, it will be easy to remember.
Here's how it's done:
1. Go to Reports.
2. Enter the Invoice list in the search area.
3. Input the Report period, and choose Run report.
4. In the reports page, click on Export, then select Export to Excel.

I'll also leave you with this detailed article that goes over further information about exporting data from QuickBooks Online: Export reports, lists, and more

If there's anything else I can help with, you can use the reply button to respond to me here. Enjoy the rest of your day!