How to scroll the background in a 2D game

I’m creating a simple 2D scroll game (like flappy bird, character goes all the way to the right and the background & obstacles are automatically and repeatedly generated)

I created three backgrounds, left, middle and right, and place them next to each other. A script called scrolling is added to each background. The script goes:

public GameObject next
public int distance

void  OnTriggerEnter2D(Collider2D c){
    next.transform.Translate(new Vector3(distance,0,0));

“left” acts as next for right, right for middle, and middle for left, so they pave the road ahead in turn on and on.
A Physics2D trigger is placed on the background (which is a rectanglular sprite), as well as a circle collider on the main character. However, when the character enters…nothing at all happened. Even the log did not show. Does anyone know why this happened?

Or, after I rethought about it, would the reason be that I simply “translate” the main character to make it move in one direction? Since I want him to move uniformly in x direction. But would this make him a kinematic object, so that the collision with the trigger doesn’t count?

If the script posted above is on the background, then the Collider2D should be on the character, right? And it should have an option in the inspector for “Trigger”, I think. I usually work with 3D and this is the way it works there. OR you could try putting the script above on the character, just change the code a bit to look like this…

void OnTriggerEnter2D(Collider2D c)
     c.transform.Translate(new Vector3(distance,0,0));
}//end of OnTriggerEnter2D()