How to control an AudioSource with an AudioClip?

Hi. I’m new to Unity and Game Development. I have a GameObject (named MusicManager) in my Scene, which has an AudioSource component on it. This has the AudioClip of the Background Music of my game. There’s another GameObject (named SFXManager) having AudioSource. This plays the UI SOund or the SFX of the game. I didn’t attach any AudioClip to the SFXManager. However, when the game starts the MusicManager starts to play the Background Music. And when the user clicks any UI Button in the game, the SFXManager plays the AudioClip. This AudioClip is played through a script with .PlayOneShot().
I want the MusicManager to lower its volume when SFXManager plays its Clip. And when the SFXManager ends its clip, the MusicManager brings its volume back to normal.

Alright so just follow this tutorial: Introduction to AUDIO in Unity - YouTube

Also, Unity has an official tutorial for this:-