androide textview randam gentrat in androide

Ill try and be specific as I can. This is my first post/question.

1. No this is not for a school or work related project.
2. I have researched and tried a number of things I saw with little results.

I am trying to create, on the Main activity, a button that generates a random number and sends the results to a Textview which is adjacent to the button on the same activity. The only thing I want to change is the contents of the TextView.

Here is my java/Main Activity code:

package com.exampal.appname;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import java.util.Random;

public class MainActivity2 extends AppCompatActivity {
    Button generate;
    TextView rendom_text;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        rendom_text = findViewById(R.id.rendom_text);
        generate = findViewById(R.id.generate);
        generate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                rendom_text.setText(generat(10));

            }
        });
    }

    private String generat(int lenth) {
        char[] chars = "ABCDEFGHIJKALMNOPQRSTUVWXYZ1234567890".toCharArray();
        StringBuilder stringBuilder = new StringBuilder();
        Random random = new Random();
        for (int j = 0; j < lenth; j++) {
            char c = chars[random.nextInt(chars.length)];
            stringBuilder.append(c);


        }


        return stringBuilder.toString();
    }
    }

This of course doesn't work, and anything I get to work opens up a new TextView and clears the current layout.

And my XML:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background"
    android:gravity="center"
    android:orientation="vertical"
    tools:context=".MainActivity2">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:orientation="vertical">

            <TextView
                android:id="@+id/rendom_text"
                android:layout_width="80pt"
                android:layout_height="50dp"
                android:layout_marginTop="10dp"
                android:background="@drawable/main_background"
                android:textColor="#fff" />


            <Button
                android:id="@+id/generate"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="50pt"
                android:background="@drawable/main_background"
                android:gravity="center"
                android:text="generate" />

        </LinearLayout>


    </ScrollView>


</LinearLayout>