Method 1:

Setup Microsoft Visio 2021 Professional.

Download the whole package and install it in your machine and activate with the key

Install the package (Double click "VisioPro2021Retail.img" and double click again "Office" folder and install either 32 bit or 64 bit)

Your Visio installation must match your office bit installation (i,e: if your Microsoft office is 64 bit then you must install 64-bit Visio 2021)

Check your Microsoft office, which bit is installed (Open MS Word --> Click File --> Click Account --> Click About office)

For both 32/64 bit Download:

https://officecdn.microsoft.com/pr/492350f6-3a01-4f97-b9c0-c7c6ddf67d60/media/en-US/VisioPro2021Retail.img