How to make endless 2D map in every direction

With the script I got, I can go to the right and it will never end, I can go up and it'll be endless too etc. but when I go somewhere and try to change direction, it's not working.

 using System.Collections.Generic;
 using System.Collections;
 using UnityEngine;
 
 public class LevelGenerator : MonoBehaviour
 {
 
     private const float PLAYER_DISTANCE_SPAWN_LEVEL_PART = 100f;
 
     [SerializeField] private Transform levelPart_Start;
     [SerializeField] private List<Transform> levelPartList;
     [SerializeField] private Transform player;
 
     
     private Vector3 lastRightPosition;
     private Vector3 lastUpPosition;
     private Vector3 lastLeftPosition;
     private Vector3 lastDownPosition;
     private Vector3 playerPosition;
 
     private void Awake()
     {
         lastRightPosition = levelPart_Start.Find("RightPosition").position;
         lastUpPosition = levelPart_Start.Find("UpPosition").position;
         lastLeftPosition = levelPart_Start.Find("LeftPosition").position;
         lastDownPosition = levelPart_Start.Find("DownPosition").position;
     }
 
     private void Update()
     {
         playerPosition = player.Find("Player").position;
 
         if (Vector3.Distance(playerPosition, lastRightPosition) < PLAYER_DISTANCE_SPAWN_LEVEL_PART)
         {
             SpawnLevelPartRight();
         }
         if (Vector3.Distance(playerPosition, lastUpPosition) < PLAYER_DISTANCE_SPAWN_LEVEL_PART)
         {
             SpawnLevelPartUp();
         }
         if (Vector3.Distance(playerPosition, lastLeftPosition) < PLAYER_DISTANCE_SPAWN_LEVEL_PART)
         {
             SpawnLevelPartLeft();
         }
         if (Vector3.Distance(playerPosition, lastDownPosition) < PLAYER_DISTANCE_SPAWN_LEVEL_PART)
         {
             SpawnLevelPartDown();
         }
     }
 
     private void SpawnLevelPartRight()
     {
         Transform chosenLevelPart = levelPartList[Random.Range(0, levelPartList.Count)];
         Transform lastLevelPartTransform = SpawnLevelPart(chosenLevelPart, lastRightPosition);
         lastRightPosition = lastLevelPartTransform.Find("RightPosition").position;
     }
     private void SpawnLevelPartUp()
     {
         Transform chosenLevelPart = levelPartList[Random.Range(0, levelPartList.Count)];
         Transform lastLevelPartTransform = SpawnLevelPart(chosenLevelPart, lastUpPosition);
         lastUpPosition = lastLevelPartTransform.Find("UpPosition").position;
     }
     private void SpawnLevelPartLeft()
     {
         Transform chosenLevelPart = levelPartList[Random.Range(0, levelPartList.Count)];
         Transform lastLevelPartTransform = SpawnLevelPart(chosenLevelPart, lastLeftPosition);
         lastLeftPosition = lastLevelPartTransform.Find("LeftPosition").position;
     }
     private void SpawnLevelPartDown()
     {
         Transform chosenLevelPart = levelPartList[Random.Range(0, levelPartList.Count)];
         Transform lastLevelPartTransform = SpawnLevelPart(chosenLevelPart, lastDownPosition);
         lastDownPosition = lastLevelPartTransform.Find("DownPosition").position;
     }
 
     private Transform SpawnLevelPart(Transform levelPart, Vector3 spawnPosition)
     {
         Transform levelPartTransform = Instantiate(levelPart, spawnPosition, Quaternion.identity);
         return levelPartTransform;
     }
 }