Make stuff not public if it doesn't need to be

Assets/Scripts/BouncyText.cs

@@ -1,11 +1,12 @@
 using TMPro;
 using UnityEngine;
 
+[RequireComponent(typeof(TextMeshProUGUI))]
 public class BouncyText : MonoBehaviour
 {
-    public float frequency = 2f;
-    public float minSize = 10f;
-    public float maxSize = 12f;
+    [SerializeField] private float frequency = 2f;
+    [SerializeField] private float minSize = 10f;
+    [SerializeField] private float maxSize = 12f;
     private TextMeshProUGUI text;
 
     void Start()