How to get information from a QR Code with Unreal Engine Android

I have very little experience with c++ or java and I want to make an Android app with Unreal Engine 5.3, which can either scan or be opened by scanning a QR Code and do something with the Information stored in the QR Code.

At first I wanted to use the QR Reader plugin by etodanik to be able to scan QR Codes, but whenever I try to add it, Unreal says it "could not be compiled. Try rebuilding from source manually." and I was unable to get around that.

Then I added an intent filter to AndroidManifest.xml via project settings:

<intent-filter>
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="citylens" />
</intent-filter>

That made it so the app starts when a QR Code containing "citylens://..." is scanned and supposedly makes the content of the QR Code become the intent.

Then I made this UPL file to add a function to GameActivity.java that should return the intent when called:

<?xml version="1.0" encoding="utf-8"?>
<root xmlns:android="http://schemas.android.com/apk/res/android">
  <init>
    <log text="IntentService additions rev2 init"/>
  </init>

  <gameActivityOnCreateAdditions>
    <insert>
        handleIntent(getIntent());
    </insert>
  </gameActivityOnCreateAdditions>

  <gameActivityOnNewIntentAdditions>
    <insert>
        handleIntent(getIntent());
    </insert>
  </gameActivityOnNewIntentAdditions>
  
  <gameActivityClassAdditions>
    <insert>
        private static String fullUrl = "";

        private void handleIntent(Intent intent) {
        Uri data = intent.getData();
        if (data != null) {
            fullUrl = data.toString(); 
        }
    }

    public native void nativeSendUriToUnreal(String uri);
    public static String getIntentData(){
        return fullUrl;
    }
    </insert>
  </gameActivityClassAdditions>
</root>

And I added following lines to Build.cs, so the UPL file would work:

string UPLPath = Utils.MakePathRelativeTo(ModuleDirectory, Target.RelativeEnginePath);

AdditionalPropertiesForReceipt.Add("AndroidPlugin", Path.Combine(UPLPath, "IntentService_UPL.xml"));

The getIntentData() function was added successfully, I checked the file, but now I am stuck trying to call it. I added the Android Native plugin and wanted to call the function using that but didn't find a way to. I have disabled proguard, because somewhere someone said that could be a problem. I also tried researching JNI and how to use it in Unreal Engine but I absolutely didn't understand any of it.

Please help me find a way to call that java function from c++ or Blueprint or if you know any other way to access the contents of the QR Code, that would also be great. Thank you for your time.