This procedure, also shown in the video, describes how to configure a standalone license file.
Please rename the license file sent to altair_lic.dat and place it in the security folder in C:\Program Files\Altair\2021\security (or any location)
Then have the following environment variables set exactly as below under System variables.
VARIABLE NAME: ALTAIR_LICENSE_PATH
VARIABLE VALUE : C:\Program Files\Altair\2021\security\altair_lic.dat or <location of license file>/altair_lic.dat
Refer the below video for reference.