This page is mostly aimed for Matomo contributors. If you are looking for instructions on how to extend the Tag Manager please also have a look at the Tag Manager Develop guides and the Tag Manager JS API reference.
Some tags, variables, or triggers may require newer browser versions though which can be fine as long as the code doesn't break in older browsers.
Open the file
It's currently required to run the command
./console tagmanager:regenerate-released-containers to update all container JS files whenever you modify any of these files.