How can I make this foreground automatically re-spawn and delete?

Here you can see my current script, at the moment you always have to press b to spawn a new floor. In addition, it will not be deleted. Can you use an algorithm for this? I'm also really a beginner so it would be nice if you could explain it in the simplest possible way or help me with the code. Thanks for all replies! This is the texture, i.e. the floor that has to be placed one after the other again and again. It serves for an endless runner :)

Code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class GroundScaler : MonoBehaviour
 {
     GameObject currentGround;
     public GameObject groundPrefab;
 
     void Start()
     {
         currentGround = GameObject.Find("Ground");
     }
 
     void Update()
     {
         if (Input.GetKeyDown(KeyCode.B)) {
             GameObject nextGround = Instantiate(groundPrefab,new Vector3(currentGround.transform.position.x + 19.8f, -4.5f, 0f), Quaternion.identity);
             currentGround = nextGround;
         }
     }
 }