How to test Turnstile on dev PC?

I’m looking to replace Captcha in our app with Turnstile. I’ve created a key and secret with the app’s domain and added the JS lib and tag to the page.

When I run the page on my dev pc, I get an error where the challenge would be:


How do you test Turnstile when the domain is localhost?

I didn’t realize you could add localhost as a domain. I thought it had to be a valid domain.

After creating the site in Turnstile and using the new site key, the widget rendered properly.