NarKampen/Assets/Scripts/Localization/ButtonLocalization.cs

using System;
using UnityEngine;
using UnityEngine.UI;

[RequireComponent(typeof(Button))]
public class ButtonLocalization : MonoBehaviour
{
    public string key;

    void Start() {
        // Get the string value from localization manager from key 
        // and set the text component text value to the  returned string value 
        GetComponent<Button>().GetComponentInChildren<Text>().text = LocalizationManager.Instance.GetText(key);
    }

    internal void UpdateText() {
        GetComponent<Button>().GetComponentInChildren<Text>().text = LocalizationManager.Instance.GetText(key);
    }
}