To activate Microsoft Office Professional Plus 2019 follow this:
1.Go to https://setup.office.com
2.Login/Register to your Microsoft Account
3.Enter the Product Key
4.Select Region and Language, then click Next
5.Download the setup from the Red Download Button
By default, the download button will download the 32-bit setup file, but below are the download links for both 32-bit and 64-bit versions:
32 bit:
https://c2rsetup.officeapps.live.com/c2r/download.aspx?ProductreleaseID=ProPlus2019Retail&language=en-US&platform=x86
64 bit:
https://c2rsetup.officeapps.live.com/c2r/download.aspx?ProductreleaseID=ProPlus2019Retail&language=en-US&platform=x64