How do I change one of the buttons in the image/card block to a secondary style button

I have used an events section and customized the card styles, I am hoping to change one of those red primary buttons to a secondary button which is in a different color and less prominent. I don't see a section to change button styles for these cards, if I was to change the theme, it will change all buttons to secondary or tertiary which is not what I am looking for.

Do you use List Section or? And what is site url?