In Scroll To Top settings you can enable / disable Scroll To Top button and modify its styles.

You can find the setting under Appearance Customize Settings Scroll To Top

1. Enable Scroll To Top: Enable / Disable scroll to top button.
2. Icon Class: Enter icon class. You can copy this class from font awesome icons.
3. Icon Size: Set icon size.
4. Scroll Top Button Padding: This will set button inner padding from all sides.
5. Border Size: Set button border size.
6. Border Radius: Set button border radius.
7. Background Color: This will apply to button background color.
8. Background Color Hover: Set button hover background color.
9. Border Color: Set button border color.
10. Border Color Hover: Set button border hover color.
11. Icon Color: Here you can set button icon color and icon color on mouse hover.