Setup Microsoft Project 2021 Standard.
Download the whole package from this below Microsoft link and install it on your machine and activate it with the key
Install the package (Double click "ProjectStd2021Retail.img" and double click again "Office" folder and install either 32 bit or 64 bit)
Your project installation must match your office bit installation (i,e: if your Microsoft office is 64 bit then you must install a 64-bit project 2021)
Check your Microsoft office, which bit is installed (Open MS Word --> Click File --> Click Account --> Click About office)
For both 32/64 bit Downloads:
https://officecdn.microsoft.com/pr/492350f6-3a01-4f97-b9c0-c7c6ddf67d60/media/en-us/ProjectStd2021Retail.img
Note: Copy the link and paste it into your browser if the download does not start automatically after clicking the link