My HTML and JS script are here. The message that you get from the first textarea works but not from the text that is actually in the Modal. I am trying to use the text that is typed into the textarea by using .value, is this right? Yes, this is in a html thing and all that stuff, it is unnecessary to include that though.

<label for="contentWebhook1">Type here what you would like to send as the message (not in modal)</label>
    <br>
    <textarea id="contentElement" name="contentWebhook1" rows="4" cols="50"></textarea> // this works fine
    <br>
    <label for="titleContent2"> This is the title of the modal</label>
    <br>
    <textarea id="contentTitle" name="titleContent2" rows="4" cols="50"></textarea>
    <br>
    <label for="contentDescription">Description</label>
    <br>

    <textarea name="contentDescription" id="contentDescriptionWebhook" cols="50" rows="3"></textarea>
    <button onclick="sendMessage()">Send message </button>
    <script>

        const messageContent = document.getElementById('contentElement');
        const messageTitle = document.getElementById('contentTitle');
        const descriptionTitle = document.getElementById('contentDescriptionWebhook');

            function sendMessage() {

            const request = new XMLHttpRequest;
             request.open("POST", "my link here, does work");
             request.setRequestHeader('Content-type', 'application/json');

              const params = {
                username: "",
                avatar_url: "",
                content: messageContent.value,
                embeds: [ myEmbed ]
             }

              request.send(JSON.stringify(params));
          }

          function hexToDecimal(hex) {
            return parseInt(hex.replace("#", ""), 16)
           }
        
            var myEmbed= {
                author: {
                name: ""
            },

            title: messageTitle.value,
            description:descriptionTitle.value, // This goes inside modal under title ^
            color: hexToDecimal("#2e5883") // This is color
        }