You can change how much vertical space your Custom Code page takes up (in pixels) right inside the Website Editor:
- In the top menu, click Pages.
- Find your Custom Code page (or the custom-code page you created) and click its name.
- Your code opens in an iframe—click inside the code area to activate the cursor.
- On the right panel, find Custom Height.
- Click it, then drag the height slider to your desired pixel height.
- Click the green Save button to apply the change.
Video walkthrough: