How to serve all resources(css, images, javascript) inside a certain folder path

I am using serverless and handlebars.
I added some routes in the serverless.yml file and it is working fine.
And the functions serve the handlebars template.
But the handlebars template uses resources like CSS, png, javascript. They all are under the root folder called “public”.
When I test, all resources folder paths do not exists and all return 404 error.
The error says that the route is not defined.
Is there any way to serve the resources directory?