Reproduction link

https://codesandbox.io/s/ng-alain-setup-dd0hq?file=/src/app/app.component.ts

Steps to reproduce

请你到你们官方给的案例中点击左边的设置主题，然后进行预览，控制台会出现window.less.modifyVars is not a function
https://ng-alain.surge.sh/#/dashboard/v1

What is expected?

可以预览主题

What is actually happening?

无法预览