I was making this site mp3 to webm for a project in discord and I can record on firefox with every device but chromium works only on windows.

When I record an audio it gets stored locally and converts to a black canvas to embed on discord then a bot just ask if the webm is ok or not and if it's accepted it gets transferred to another channel.

It need to be a embed file because bots on discord.js or py can't manipulate audios yet

let mediaRecorder;
let audioChunks = [];
let audioBlob;
let canvas;
let canvasStream;
let audioStream;

function createCanvasWithNickname(name) {
    canvas = document.createElement('canvas');
    canvas.width = 400;
    canvas.height = 144;
    const ctx = canvas.getContext('2d');
    ctx.fillStyle = 'black';
    ctx.fillRect(0, 0, 400, 144); 
    ctx.fillStyle = 'white';  
    ctx.font = '24px Arial';  
    ctx.textAlign = 'center'; 
    ctx.textBaseline = 'middle'; 
    ctx.fillText(name, 200, 72); 

    return canvas.captureStream(30); 
}

// Funzione per inizializzare l'audio con un metodo alternativo
async function initializeAudio() {
    const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
    audioStream = stream;
}

document.getElementById('recordButton').addEventListener('click', async () => {
    const name = document.getElementById('nameInput').value.trim();

    canvasStream = createCanvasWithNickname(name);
    await initializeAudio();
    const combinedStream = new MediaStream([...canvasStream.getTracks(), ...audioStream.getTracks()]);
    mediaRecorder = new MediaRecorder(combinedStream, { mimeType: 'video/webm' });
    mediaRecorder.start();
    mediaRecorder.ondataavailable = (event) => {
        audioChunks.push(event.data);
    };

    mediaRecorder.onstop = () => {
        audioBlob = new Blob(audioChunks, { type: 'video/webm' });
        const audioUrl = URL.createObjectURL(audioBlob);
        document.getElementById('audioPreview').src = audioUrl;

        document.getElementById('recordButton').disabled = false;
        document.getElementById('stopButton').disabled = true;
        document.getElementById('sendButton').disabled = false;
    };

    document.getElementById('recordButton').disabled = true;
    document.getElementById('stopButton').disabled = false;
});

document.getElementById('stopButton').addEventListener('click', () => {
    mediaRecorder.stop();
});

document.getElementById('sendButton').addEventListener('click', async () => {
    const name = document.getElementById('nameInput').value.trim();

    if (!name) {
        alert('Devi inserire un nickname!');
        return; 
    }

    const formData = new FormData();
    formData.append('file', audioBlob, 'audio.webm');
    formData.append('username', name);

    try {
        await fetch('webhookhere', {
            method: 'POST',
            body: formData
        });
        alert('Audio inviato a Discord con successo!');
    } catch (error) {
        console.error('Errore durante l\'invio del file:', error);
    }
});

I tried lots of workaround and did research but all I find are people with the same problem and no answers