We provide both email and phone number authentication. We think that phone numbers works best for our target users, but for developers, we think that emails are more useful.
I only see the email option on https://dev.cotter.app/signin . Also, when I get to that page from another page on your site and cursor into the email field, the browser back button no longer works. it just refreshes the page even if I hit it a bunch quickly
You can choose whether you want your clients to login using email or phone number when you're integrating our SDK into your website or app.
For our developer account, we choose to use email login.
I'll look into the back button problem, thanks for letting me know!