I would like to send a webhook response to the Accepted page when using a webhook, displaying "Working on" first and "Work completed" at the end

I have arranged the layout as shown in the image, and I know how to display “Working on” on the page to the right using module [2] (webhook response).

Next, after module [5] operates, when module [10] (webhook response) is triggered, I would like to change the text “Working on” to “Work completed.”

Below is the “Body” that I put into module [2]. I wrote it in this format because I plan to add animation effects later through a script.

What would be the best approach for this?

<!DOCTYPE html>
<html lang="ko">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>work</title>
    <style>
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            flex-direction: column;
            text-align: center;
        }

        .loading-text {
            font-size: 20pt;
            font-weight: bold;
        }

        .sub-text-container {
            display: flex;
            align-items: center;
            margin-top: 10px;
        }

        .sub-text, .timer {
            font-size: 12pt;
            font-weight: normal;
        }

        .timer {
            margin-left: 20px;
        }
    </style>
</head>
<body>
    <div class="loading-text" id="loadingMessage">Working on</div>
</body>
</html>