In browser developer tools, I checked xhr tab in networking, the request sent as supposed.

while debugging: upload mehtod is invoked but uploadedFile is null

project has working files uploading via p:fileUpload, so I think filters troubles are passed.

here are:

bean:

import javax.servlet.http.Part;

import com.d2m.view.bean.LetterWFBean;

@Named
@RequestScoped
public class AudioFileUpload {
    private Part uploadedFile ;//+setter/getter
    @Inject
     private LetterBean letterBean;
    public void upload() throws IOException{
        byte[] blob = uploadedFile.getInputStream().readAllBytes();
        letterBean.setAudioNote(blob);
    }
 ...
}

facelet:

<h:form id="hiddenAudioUploadForm" enctype="multipart/form-data" styleClass="ui-helper-hidden">
           <h:inputFile id="audioFile" value="#{audioFileUpload.uploadedFile}" />
           <p:remoteCommand name="hiddenAudioUploadCommand" action="#{audioFileUpload.upload}" process="@form" update="@none" />                                      
    </h:form>
        ...
    <p:button id="uploadAudio_CL" onclick="uploadAudioFile();return false;" icon="fa fa-check" />

JS:

function addAudioFileToUploadFiles(){
    const dataTransfer = new DataTransfer(); 
    dataTransfer.items.add(new File([ base64AudioBlob ], "a.ogg", { type: "audio/webm" }));
    document.getElementById("hiddenAudioUploadForm:audioFile").files = dataTransfer.files;
}
async function uploadAudioFile(){
    addAudioFileToUploadFiles();
    hiddenAudioUploadCommand();
}

Thanks-at least for reading!