I got the "place order" screen and needed to press the button at the bottom that said "PLACE ORDER". But I couldn't see the button - it was off the bottom of the page and there was no scroll bar to get me there. I had to guess how many tabs would get me there and then hit enter. How do I scroll down when there is no scroll bar and the up and down arrows do nothing and page up and page down do nothing?
If you're referring to a browser, you can also try zooming the browser out. All modern browsers should have a zoom feature. Zooming out makes everything smaller and may bring features lower down into view.
How to zoom depends on whether you are using Mac or Windows.
In some browsers, in Windows you can zoom out by repeatedly pressing Ctrl and the minus (-) key simultaneously. Ctrl plus 0 returns it back to baseline.
In Windows 10 you can check your overall display settings at Settings > System > Display.
Check your settings there for "Scale and layout" and "screen resolution".
Do you have the scale set for greater than 100%? If so, try lowering it temporarily.