It seems that you are experiencing a display issue with the expense pop-up window in QuickBooks Online, Carol. I'll provide you with the steps to fix this. 

Since you're experiencing the issue where the Apply button is located below the screen and is difficult to access, this could be due to the resolution or display settings of your device. With this, I recommend checking your Zoom function settings and zooming it out to reduce the display in your browser. You may refer to the steps below to do so:

In Microsoft Edge

1. Click the Three dots icon in the upper right-hand corner to access the Settings menu.
2. In the Zoom section, select the - button, or simply click Ctrl + Minus key (-) on your keyboard to reduce the screen display.

In Google Chrome 

1. Click the More  icon at the top right corner.
2. In the Zoom section, select the - button to reduce the screen display.

In Mozilla Firefox

1. Click the Menu  icon on the right.
2. In the Zoom section, select the - button to reduce the screen display.

Additionally, QuickBooks Online requires a Screen resolution set to 1024x768 or higher and Dots-per-inch (DPI) set to Normal or 100% to display all pages properly. You can refer to this link for more details on how to check and manage your computer settings: Unable to see the entire page in QuickBooks Online.

Moreover, I'll leave this helpful article if you're experiencing pages that aren't fully loading while accessing the program and how to fix them: QuickBooks Online doesn't load correctly or has blank pages.

Drop a comment below if you need anything else or need further assistance managing your monitor and browser display when running QuickBooks. I'll always be right here to help you.