How to validate multiple forms with the same class?

Question

Validation

1. There are several forms, each of which contains the class ._form
2. There is a function in js that validates forms, with the above class.

Essence of the question. How to validate ALL forms with ._form class.
So far, only the first one has been validated. For validation, I use the justValidate plugin.

https://codepen.io/thedext/pen/WNZOrvP?editors=1111