Databases

In TMPEffects, the set of animations a TMPAnimator can use (or the set of commands a TMPWriter can use) is defined by the database it uses.

Databases, like animations and commands, are ScriptableObject assets.
You can create a new database by right-clicking in your project view, then Create -> TMPEffects -> Database, again, just like animations and commands.
You can then add any animation / command to your database, and assign it to a TMPAnimator / TMPWriter component in the inspector.
Of course, you can also modify the built-in default databases any way you want, or assign different databases to be used as default database in the TMPEffects settings (in the top bar, Edit -> Preferences -> TMPEffects).

SceneAnimations and SceneCommands are separate from databases and are instead added to a dictionary in the component's inspector; see the individual sections on them.