How to make a coin bank?

Hello so im making an endless runner game its low poly and i made coin system so when u pick up a coin u get 1 point and its all cool but when u go to the menu and u look at how many coins u got it is the coins u just picked up and not in the previous round so what im trying to say is when u collect coins in a round and die and u go to the menu i want those coins to add up to previous coins collected in previous round if you get me what im trying to say so here is my script

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class GameManager : MonoBehaviour
 {
     public static GameManager instance = null;
 
     public GameObject scoreTextObject;
 
     int score;
     Text scoreText;
 
 
     void Awake()
     {
         if (instance == null)
             instance = this;
         else if (instance != null)
             Destroy(gameObject);
 
         scoreText = scoreTextObject.GetComponent<Text>();
         scoreText.text = " " + score.ToString();
     }
 
     public void Collect(int passedValue, GameObject passedObject)
     {
         passedObject.GetComponent<Renderer> ().enabled = false;
         passedObject.GetComponent<Collider>().enabled = false;
         Destroy(passedObject, 1.0f);
 
         if (PlayerPrefs.GetFloat(" ") + score)
         PlayerPrefs.SetFloat(" ", score);
 
         score = score + passedValue;
         scoreText.text = ": " + score.ToString();
         // update our score UI
     }
 }
 

And i get this error;cannot implicitly convert float to bool Can anyone please help me?