Convert java runtime error codes to plain english

Hi everyone!

I have a question about my application to ask. I hope someone can help! I am trying to implement interstitial ads by making use of Androidapi.JNI.AdMob. The onAdFailedToLoad method gets called with error code 1. My question is: How can I convert error code  1 to plain English? Does anyone maybe know of a website or Delphi class that can do this conversion. This is my only hope in trying to debug this problem. I also want to know: Is this a normal java runtime error code or is it some other error code that I don't know about. I use Delphi Rio 10.3 Community. Thank you for your help!

Here is my code:

unit Main;

interface

uses
  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
  FMX.Controls.Presentation, FMX.ScrollBox, FMX.Memo, FMX.StdCtrls, FMX.Objects,
  System.Math, FMX.Effects, FMX.Filter.Effects, FMX.Ani, System.SyncObjs
  
  {$IfDef Android},
  AudioManager, AndroidApi.JNI.AdMob, Androidapi.JNI.JavaTypes, Androidapi.JNIBridge,

  FMX.Advertising,

  FMX.Platform.Android,  Androidapi.JNI.PlayServices,

  Androidapi.JNI.GraphicsContentViewText,

  FMX.Helpers.Android,
  Androidapi.Helpers,

  Androidapi.JNI.App,
  Androidapi.JNI.Net, Androidapi.JNI.Util, Androidapi.JNI.Os,

  Androidapi.JNI.Telephony,

  Androidapi.JNI.Widget,
  Androidapi.JNI.Location,

  Androidapi.JNI.Embarcadero
 {$EndIf};
 
Type 
 TInterstitialAdListener = class(TJavaLocal, JIAdListener)
  private
    FAd : JInterstitialAd;
  public
    Constructor Create(Pa : JInterStitialAd);
    procedure onAdClosed; cdecl;
    procedure onAdFailedToLoad(errorCode: Integer); cdecl;
    procedure onAdLeftApplication; cdecl;
    procedure onAdOpened; cdecl;
    procedure onAdLoaded; cdecl;
  end;(*Class*)
  
TFormMain = class(TForm)  
  procedure ButtonTestsAdClick(Sender: TObject);
End;(*Class*)  

Var
 FormMain : TFormMain;
 
 {$IfDef Android}
   FJInterstitialAd : JInterstitialAd;
   FInterstitialAdListener : TInterstitialAdListener;
   RequestBuilder : JAdRequest_Builder;
   FJAdRequest : JAdRequest;
 {$EndIf}
  
implementation

{$R *.fmx}

{$IfDef Android}
  Constructor TInterstitialAdListener.Create(Pa : JInterStitialAd);
  begin
   inherited Create;
   FAD := Pa;
  End;(*Constructor*)

  Procedure TInterstitialAdListener.onAdClosed;
  begin
   ShowMessage('Ad closed');
  End;(*Procedure*)

  Procedure TInterstitialAdListener.onAdFailedToLoad(errorCode: Integer);
  begin
   ShowMessage('Ad failed to load with error code: ' + IntToStr(errorCode));
  end;(*Procedure*)

  procedure TInterstitialAdListener.onAdLeftApplication;
  begin
   ShowMessage('Left application');
  end;(*Procedure*)

  procedure TInterstitialAdListener.onAdOpened;
  begin
   ShowMessage('On ad opened');
  end;(*Procedure*)

  procedure TInterstitialAdListener.onAdLoaded;
  begin
   FAd.show;
  end;(*Procedure*)  

procedure TFormMain.ButtonTestAdClick(Sender: TObject);
begin
 {$IfDef Android}
  CallInUIThreadAndWaitFinishing(
  Procedure
  Begin
    FJInterstitialAd := TJInterstitialAd.JavaClass.init(MainActivity);
    FJInterstitialAd.setAdUnitId(StringToJString('xxx_Your_Specific_AdUnitId_xxx'));
    RequestBuilder := TJAdRequest_Builder.JavaClass.init;
    if (*FTestMode = true*)(1=1) {I am trying to run this interstitial ad in tesy mode}
     then begin
           RequestBuilder.addTestDevice(TJAdRequest.JavaClass.DEVICE_ID_EMULATOR);
           RequestBuilder.addTestDevice(MainActivity.getDeviceID);
          end;(*If*)
    FJAdRequest := RequestBuilder.build;
    FInterstitialAdListener := TInterstitialAdListener.Create(FJInterstitialAd);
    FJInterstitialAd.setAdListener(TJAdListenerAdapter.JavaClass.init(FInterstitialAdListener));
    FJInterstitialAd.loadAd(FJAdRequest);
  End);
 {$EndIf}
end;(*Procedure*)  

end.(*Main Program*)