Using Google Fonts in Oracle APEX

1. Pick the font you want from Google Fonts. In this example, I picked Roboto, and you should add all the styles to the font family.

2. Add this CSS via Theme Roller->Custom CSS

@import url('https://fonts.googleapis.com/css2?family=Roboto:ital,wght@0,100;0,300;0,400;0,500;0,700;0,900;1,100;1,300;1,400;1,500;1,700;1,900&display=swap');
:root {
  --a-base-font-family: 'Roboto', sans-serif;
}