ScriptableObjects for audio can be created by "Right Clicking anywhere in the project panel > Create > Sound" or duplicating an already created SO.
ScriptableObjects will all have specific settings that control the audio clip which is used, that you can change, the volume, pitch, variance and whether it can loop. All features of the default "AudioSource" component.
In the AudioManager is good to add the size of the Sounds array to the number of sounds which will play within this system. By default it has 5 SO audio clips, these should be added to access them all.
Look at the inspector of the any interactive object with the "FuseItem" script and this will have slots for specific SO sound effects that you can add! This allows you to play that specific SO from the audio manager.
Referencing the Audio Manager Use the code, within your scripts to reference your sounds to play. This code will play the references ScriptableObject sound effect.