Need help with foreground service

Can anyone please help me. Completely new to Android development, am currently using Kotlin. I made my very first online streaming media app, but whenever i change apps, or turn off the screen, the audio stops. I've tried looking through the Android docs, but i can't understand it. Can anyone please help me!

Code (Java):

1. package com.example.al_bunyan
2.  
3. import android.app.Dialog
4. import android.content.Intent
5. import android.graphics.Color
6. import android.graphics.drawable.AnimationDrawable
7. import android.media.MediaPlayer
8. import android.net.Uri
9. import androidx.appcompat.app.AppCompatActivity
10. import android.os.Bundle
11. import android.view.View
12. import android.widget.Button
13. import android.widget.ImageView
14. import android.widget.RelativeLayout
15. import android.widget.VideoView
16. import java.time.Instant
17.  
18. class MainActivity : AppCompatActivity() {
19.  
20.     override fun onCreate(savedInstanceState: Bundle?) {
21.         super.onCreate(savedInstanceState)
22.         setContentView(R.layout.activity_main)
23.  
24.  
25.         var web_btn = findViewById<Button>(R.id.link_btn)
26.  
27.  
28.  
29.         web_btn.setOnClickListener {
30.  
31.  
32.             var intent = Intent(this@MainActivity, AlbunyaWebview::class.java)
33.             startActivity(intent)
34.         }
35.      
36.  
37.     }
38.  
39.     fun video_check(view:View) {
40.  
41.         val fm105 = findViewById<Button>(R.id.fm105_7)
42.         val alert = Dialog(this@MainActivity)
43.         alert.setContentView(R.layout.audio_play)
44.         val video = alert.findViewById<VideoView>(R.id.video_alert)
45.         val play = alert.findViewById<Button>(R.id.play)
46.         val pause = alert.findViewById<Button>(R.id.pause)
47.         val resume = alert.findViewById<Button>(R.id.resume)
48.  
49.  
50.  
51.         if (fm105.isPressed) {
52.  
53.             val video_1 = Uri.parse("http://albunyan.fm:8000/live")
54.             video.setVideoURI(video_1)
55.  
56.             alert.show()
57.  
58.             play.setOnClickListener {
59.  
60.                 video.start()
61.             }
62.  
63.             pause.setOnClickListener {
64.  
65.                 video.pause()
66.             }
67.  
68.             resume.setOnClickListener {
69.  
70.                 video.start()
71.             }
72.  
73.         }
74.     }
75.  
76. }

 

Thank you so much bro. Really appreciate your help