Form sending data to Email

Colleagues, on the website pro.online-osago.ru/osago... there is 98% typeset form. Need to revive it and ensure that all the data just came in the mail.

That is:
- typeset form (bootstrap 4)
- 90% composed php file to send
- have connected the js file, which must be adapted to this form

Requirements:
- all fields are mandatory. Needs to be review and highlight what is not full (using the standard check-in bootstrap or using a separate class in css)
- after you submit should open a separate page: /osagokurs_ok (to do)