This is old deprecated code. Also it features some of the worst coding in the history of JS/HTML (imagine trying to beat JS into being object oriented!) It will probably still work so long as you set the year to the correct time but otherwise it needs a deep rewrite.
Download/clone all of the files from this repository into a single folder.
Go to chrome://extensions. Make sure "Developer Mode" is turned on.
Click "Load unpacked." Locate the folder in the file browser that appears, and select the folder.
Once the extension is loaded, this should appear in the extensions screen:
Select the extension in the extensions tab (the puzzle piece).
Input a team number and event code to be displayed and click Open.
Note: Currently an event MUST be from the 2022 season.
Event codes can be found at (https://ftc-events.firstinspires.org). You can type your team number in the search bar at the top and select an event you want (again, currently only from the 2022 season).