Unable to embed apache superset dashboard, getting 401 UNAUTHORIZED in the /api/v1/dashboard/

I am trying to embed dashboard from my app's instance of superset, I am unable to view the dashboard on my application,

I am getting 401 unauthorized error, even if i am sending the authorization header which i am getting from the fetch_guest_token() function.

Where I am I going wrong? Or is there any other way to set the authorization header?

Response: {
"msg": "Missing Authorization Header" 
}

Request URL: https://aether.ithena.io/api/v1/dashboard/
Request Method: GET
Status Code: 401 UNAUTHORIZED

async function embedDashboard() {
    try {
        updateStatus('Starting dashboard embed...');
        console.log('Starting dashboard embed...');
        
        const embedConfig = {
            id: DASHBOARD_CONFIG.id,
            supersetDomain: DASHBOARD_CONFIG.supersetDomain,
            mountPoint: document.getElementById("superset-container"),
            fetchGuestToken: fetchGuestToken, //auth 
            
            dashboardUiConfig: {
                hideTitle: false,
                hideTab: false,
                hideChartControls: false,
                filters: {
                    expanded: false,
                    visible: true
                }
            }
        };
        
        console.log('Embedding dashboard with config:', embedConfig);
        
        const dashboard = await supersetEmbeddedSdk.embedDashboard(embedConfig);
        
        console.log('Dashboard embedded successfully!', dashboard);
        updateStatus('Dashboard loaded successfully!', 'success');
        
    }

async function fetchGuestToken() {
    try {
        updateStatus('Requesting guest token...');
        console.log('Fetching guest token from Node.js server...');
        
        const response = await fetch(`${DASHBOARD_CONFIG.serverUrl}/api/guest-token`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
            },
            body: JSON.stringify({
                user_info: {
                    username: "guest_user",
                    firstName: "Guest",
                    lastName: "User",
                    roles: ["Admin"]
                },
                resources: [{ 
                    type: "dashboard", 
                    id: DASHBOARD_CONFIG.id 
                }],
                "rls": []
            })
        });
        
        if (!response.ok) {
            const errorData = await response.json();
            throw new Error(`Server error: ${errorData.error || response.status}`);
        }
        
        const data = await response.json();
        console.log('Guest token received');
        updateStatus('Guest token received, embedding dashboard...', 'success');
        
        return data.token;
        
    } catch (error) {
        console.error('Failed to fetch guest token:', error);
        updateStatus(`Failed to get guest token: ${error.message}`, 'error');
        throw error;
    }
}