CSP was delivered via a meta element outside document head

Custom Code
I have the below code in a WebView widget, but I am stuck with an error:
"The Content Security Policy 'default-src 'self' 'unsafe-inline' 'unsafe-eval' https://static.moonpay.com https://www.gstatic.com' was delivered via a <meta> element outside the document's <head>, which is disallowed. The policy has been ignored."

<html>
<head>
    <title>MoonPay SDK</title>
    <meta http-equiv="Content-Security-Policy" content="default-src 'self' 'unsafe-inline' 'unsafe-eval' https://static.moonpay.com https://www.gstatic.com">

    <script defer src="https://static.moonpay.com/web-sdk/v1/moonpay-web-sdk.min.js"></script> 
    <script src="https://www.gstatic.com/firebasejs/8.2.1/firebase-app.js"></script>
    <script src="https://www.gstatic.com/firebasejs/8.2.1/firebase-auth.js"></script>
</head>
<body>
    <!--Button that triggers the MoonPay SDK-->
    <button id="moonpay-button">Buy with MoonPay</button>

    <!--Initialize the SDK in your application with the flow, environment, variant, and any parameters related to Buy, Sell or Swap.-->
    <script>
        window.onload = function() {
            // Initialize Firebase
            var firebaseConfig = {
                  //firebase config
                };

            firebase.initializeApp(firebaseConfig);

            // Fetch the user's email from Firebase
            var user = firebase.auth().currentUser;
            var userEmail = user ? user.email : '[email protected]'; // replace '[email protected]' with a default email

            const moonpaySdk = window.MoonPayWebSdk.init({  
                flow: 'buy',
                environment: 'sandbox',
                variant: 'overlay',  
                params: {  
                    apiKey: 'apikey',
                    theme: 'dark',
                    baseCurrencyCode: 'usd',
                    baseCurrencyAmount: '100',
                    defaultCurrencyCode: 'eth',
                    externalCustomerId: userEmail
                },
                debug: true
            });

            // Add event listener to the button
            document.getElementById('moonpay-button').addEventListener('click', function() {
                moonpaySdk.show();
            });
        }
    </script>
</body>
</html>
What have you tried so far?

Tried adding meta tags, I am just testing some flows

Did you check FlutterFlow's Documentation for this topic?
No
2