Sending, receiving, and organizing email in Outlook on the web for business
From your description, this appears to be the Optional Connected Experiences consent dialog in Outlook. As far as I know, buttons such as Accept, Continue, or OK are located at the bottom of the dialog and may require scrolling to become visible. Since the lab window appears fairly small, the lower portion of the dialog may not be fully displayed.
You could try to:
Zoom out the page by pressing Ctrl + - a few times (for example, down to 50-67%) and check whether the bottom of the dialog becomes visible.
Scroll within the dialog itself by placing your cursor over the content area and scrolling down, or by dragging the scroll bar on the right all the way to the bottom.
Use keyboard navigation by pressing Tab repeatedly to move through the available options, then press Enter if the action button becomes selected.
Refresh the page (F5) and try again.
If the issue persists, try accessing it using a different browser to determine whether the dialog renders correctly there.
I also noticed the "Poor Connection" warning at the top of the lab environment. An unstable connection may cause buttons or interface actions to respond slowly or fail to register immediately, so it may help to wait a few seconds after each action to see whether the page updates.
You could give it a try and let me know how it goes.