How to enable Google reCAPTCHA for login/register?

To enable reCAPTCHA: 

Jobster Settings > General Settings > Keys > Fill reCaptcha v2 API key and reCaptcha v2 API secret (you have to click those links and follow the instructions to create some)

Jobster Settings > General Settings > User > Login & Register > Enable reCaptcha v2 on registration/login page