I would like to buy a .app domain and connect it to a heroku-hosted application. When I want to buy .app domain on Google domains (or anywhere else), I can read "For *.app, you need an SSL certificate before you can launch a website". If I buy that domain, will I be able to use it with Heroku application? If not, what do I need to do in order to be able to connect .app domain with heroku app?
yes, you can have a custom domain without incurring extra charges
all the configurations and setup details are detailed in the linked article