Angular multiple projects

How we can work with multiple projects in one workspace with lazy loading router

I use angualr cli to create new angular app like this

ng new main-app

then use angular cli to generate projects like this

ng generate application app-a
ng generate application app-b

i need to make lazy loading between these apps (main-app , app-a , app-b)
structure of the projects like the below

projects/app-a/src/app
projects/app-b/src/app
src/app

how i can navigate between app-a and app-b

i tried to navigate between app-a and app-b using lazy loading between appAModule and appBModule but it's doesn't work