It is available for free as a separate download for anyone who has bought FM21 through Steam library under tools.
How to find it in a glance:
Open Steam -> Library -> Tools -> Football Manager 2021 Editor
Step by Step InstructionsStep 1: To find and download the pre-game editor for Football Manager 2021, you'll need to log into the Steam desktop app first.
Step 2: On the top-left menu (Store/Library/Community/User), go on Library.
Step 3: Select "Games" then tick "Tools".
Step 4: You will now see a number of titles, just scroll down to Football Manager 2021 Editor, right click on it and finally select install.
The download will now proceed, and you'll be able to use it.
The initial run may require to install direct X files.
For optimal performance it is recommended that you use the FM 2021 Editor on a high-end machine with at least 2GB RAM or more.
Due to massive amount of data stored in the Football Manager 2021 database you may experience poor or slow performance on low-end systems.