Go to the Endless Release.
Download the appropriate zip file, ie: endless-cli-Windows-x86_64.zip.
Unzip the downloaded file.
Move the extracted Endless binary file, ie: endless.exe into your preferred folder.
Right click, then copy the path to the executable.
Ex. C:\Users\<username>\Downloads\endless.exe.
Open PowerShell via the Start Menu.
Verify the installation by running the help command.
Ex. C:\Users\<username>\Downloads\endless.exe --help.