There are several ways to achieve this. We describe one method using the .htaccess file in the following knowledge base article: https://support.sbpro.io/knowledge-base/make-sb-pro-force-redirect-to-https-instead-of-using-http/
FAQ: Can I use a WHM/cPanel server to host Pagestead?
FAQ: What server / VPS and hosting company do you recommend we use to run Pagestead?
FAQ: Why are my page and template thumbnails not being generated?
FAQ: Can we add additional public pages to Pagestead, like a custom home page?
FAQ: Site and template thumbnails are not getting generated; why is that?
FAQ: Can I import existing sites into Pagestead?