Opening a PDF on Android

I want to make an App, where you can open the implemented PDFs and read them.

The following Code works on Unity-Editor on Windows, but NOT on my Android-Build.

    public void Button_Test()
    {
        try
        {
            TextAsset pdfTem = Resources.Load("Recipes/a", typeof(TextAsset)) as TextAsset;
            File.WriteAllBytes(Application.persistentDataPath + "/" + "a" + ".pdf", pdfTem.bytes);
            Application.OpenURL(Application.persistentDataPath + "/" + "a" + ".pdf");
        }
        catch (Exception _ex)
        {
            m_Text_Debug.text = _ex.ToString();
        }


    }

It doesn’t show an Exception, although nothing happens. Can someone help?

Duplicated question.

Removed.