My speaker is not working good

@abdulabdul66380 have you cleaned the speaker opening on the external phone. Make sure that it is clean. Of course, check all your audio settings as well to ensure proper sound playback. If none of that helps, you may consider replacing the speaker. Check on something like this video for more info.

You can always check the Samsung Flowchart and see if that will help you out if you need to go to a board level repair.

Use the search function on your PDF reader to find the components in this document Component Layout you need to check on.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!