How to properly set up scss build with Gulp?

Question

gulp.js

I need to build a project with Tabler.io for Laravel by changing the color variables and so on in variables.scss
As a given - using Gulp.

I load tabler ..and
yarn add [email protected]

bootstrap
yarn add bootstrap

they are loaded in node_modules .

Now I need to somehow collect the styles by first changing variables.scss
I copy variables.scss from node_modules/tabler/scss to resources/scss and change it.

What is the correct way to write a task in gulp now?