Transfer player's data from scene to scene [duplicate]

so I have a little project where I have 3 scenes - gameplay one with player and it's script, main menu with 2 buttons "Play" and "Shop" and shop scene with 2 buttons "Buy HP" and "Buy Speed". So I want to have an opportunity to change some stats on player from shop scene. I used PlayerPrefs for this and setted values in Start method of player's script.

[SerializeField] private int maxHP = 1; [SerializeField] private int hp = 0; [SerializeField] private float attackTimer = 2f; void Start() { if(maxHP == 1) { PlayerPrefs.SetInt("maxHP", maxHP); } else { if(PlayerPrefs.GetInt("maxHP") != null) { maxHP = PlayerPrefs.GetInt("maxHP"); } } PlayerPrefs.SetFloat("attackCD", attackTimer); rb = GetComponent<Rigidbody2D>(); currentAttackTimer = attackTimer; hp = maxHP; } 

so player's Start() method looks like this. Cause attackTimer is changing in the same way, I will put only maxHP as an example:

public void BuyHP() { if(PlayerPrefs.GetInt("maxHP") < 5) { int tmpHP = PlayerPrefs.GetInt("maxHP"); tmpHP++; PlayerPrefs.SetInt("maxHP", tmpHP); hpText.text = PlayerPrefs.GetInt("maxHP").ToString() + "/5"; } } 

this script is on button, it works to change value up to 5 times and rewrite it in "maxHP" key, but at the start of a gameplay scene I have maxHP = 1 anyway. Can somebody help me out and explain, mby I don't really know how PlayerPrefs works? Thx in advance