How can I change the style of the quantity button on my website?

Store Design
1

I have the normal - and + default quantity selector, I’m looking to change it to this style of quantity Button found on thus website https://shopthrillze.com/products/led-purge-mask/

Idk if they are using an App,Code, or theme for this. Please let me know. I would love to know the app for this

2

Hi @NolanC this can be done using custom coding, there is no need of external app.