JS changing text inside button

I wanted to change text of slick arrows but inner html and textcontent properties dont work it shows in console but i dont understand why it dont work maybe anypne know what my problem or other way to do what i want

Typically, there's a :before that adds icons. maybe you need to target that.

FYI, this is an Appwrite (https://appwrite.io/) discord server, for general HTML/CSS questions, you might find more help in a different discord server