How to import css from node_modules using sass or less?

Decided to style the grid according to instructions.
https://github.com/swimlane/ngx-datatable/blob/mas...

Set grid via npm.
Installed gulp.

Created scss, added to it

@import '[email protected]/ngx-datatable/release/index.css'; @import '[email protected]/ngx-datatable/release/themes/material.css'; @import '[email protected]/ngx-datatable/release/assets/icons.css';

But in the output css file get

@import url([email protected]/ngx-datatable/release/index.css); @import url([email protected]/ngx-datatable/release/themes/material.css); @import url([email protected]/ngx-datatable/release/assets/icons.css);

With Less about the same situation(

Other rules of sass or less normally interpreted.
Please tell me how to import?