If you wish to remove all other elements from the webpage except for the text box and the button, you can simply modify the HTML to only include those elements. Here's an updated version of the code:
```html
Send to Discord Webhook
```
This code now centers the text box and button on a white background, with no additional content. The style is applied inline for simplicity, but you can move it to an external stylesheet if you prefer. The form still sends the input text to the specified Discord webhook when the button is clicked.