You'll need to click the F2 key in your keyboard to open the Product Information window in your QuickBooks Desktop (QBDT) account. From there, you can see the product number and license number of your QBDT account. I've added an image below for reference.
If you're referring to installing your QuickBooks and can't locate your license and product number, you can refer to the steps provided by my colleague ShiellaGraceA above.
However, if you're using QuickBooks Online (QBO), you only need your Company ID. To know your company ID, just click Ctrl + Alt + ? (question mark) in your keyboard. You can also check this article for more details: Find your QuickBooks Online Company ID.
As always, visit our Help articles page to learn and read some related articles for future reference.
Don't hesitate to reach out to us if you need further assistance. We're always here to help.