using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement:
public class Menu : MonoBehaviour
{
void Start(){
}
void Update(){
}
// Voidy do guzików //
void GrajBtn()
{
SceneManager.LoadScene(1)
}
}
This line using UnityEngine.SceneManagement: is wrong. You have a : at the end of the line instead of a ; using UnityEngine.SceneManagement;
Also this line SceneManager.LoadScene(1) is missing a ; from the end of it.
Both of the above are speculation as you haven’t given us any information on what is actually happening.