Welcome back, sylvainP17.
Since you've already installed QuickBooks Desktop for Mac 2019, you can go to this link to check your license and the product number: License and product numbers.
Also, I'll leave you with a guide to know anything about QuickBooks Desktop for Mac: QuickBooks Desktop Mac 2021 User’s Guide.
Feel free to go back to this thread if you need anything else while working with the QuickBooks Desktop software. Have a good one.
