This is a good option if you do not want to link the license you purchased with your Microsoft account.
Step 1: Choose your language and click on the link to download the ISO/IMG file. The download process should start after clicking on the link.
Here is a list of official Microsoft links to download the Office 2019 Professional Plus ISO file.
Choose your language, click on the link to start the download and wait for the download to finish to mount the file. It may take 10 to 20 minutes, depending on your Internet speed.