If you only have the mySQLi extensions, you can certainly use the Insert/Update behaviors to use your form to submit info to a database. However you would need to build your own form and add the reCaptcha code manually. You'd be best to follow a tutorial such as this one: https://codeforgeek.com/google-recaptcha-tutorial/. My reCaptcha widgets are all built into Universal Email code so I don't think my examples would help you.