If you’re customizing the theme and want to override theme function, we’d suggest you to use child theme instead of change the original code. Benefit? It help you to prevent the change when you need to update the theme
In this case I will give an example of Modernize. If you’re using other themes, just change the name ‘modernize’ to yours.
1.) Create a new folder in folder ‘wp-content/themes/’, you can name anything.
2.) Create the file ‘style.css’ and put this code inside