Error trying to find file in Android app with File Provider

Hello, I'm having a hard time messing with FileProvider.

The file gets created because I manually checked the directories. I put some logs to see what happens but even then I can not understand why it does not find

I generate a PDF but can not open it right away. Here is the code below.

AndroidManifest.xml

 <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="${applicationId}.provider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/filepaths" />
        </provider>

filepaths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-files-path name="files" path="."/>
</paths>

creation of pdf file

File docsFolder = new File(Environment.getExternalStorageDirectory()+"/compras");
        if (!docsFolder.exists()) {
            docsFolder.mkdir();
            Log.i(TAG, "Created a new directory for PDF");
        }

        comprovante = new File(docsFolder.getAbsolutePath(),"comprovante.pdf");

Attempt to load the file

Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
Uri uri = FileProvider.getUriForFile(ComprasComprovanteActivity.this, BuildConfig.APPLICATION_ID + ".provider",comprovante);

The error

Failed to find configured root that contains /storage/emulated/0/compras/comprovante.pdf