What is the best way to set up a self-signed certificate when binding to 0.0.0.0?

[ayushn21]

I've got a self-signed certificate set up using the localhost gem. When I run bundle exec falcon serve, my site works fine, and I don't get a security warning in the browser.

If I run bundle exec falcon serve -b https://0.0.0.0 -p 4000, I get a security warning in the browser, even when accessing the site via https://localhost:4000.

Is there any way to easily set up a self-signed certificate so I can bind to 0.0.0.0 and still avoid the browser warning?