https://diia.gov.ua/services/zayava-na-shlyub - here you can send an online application for marriage registration in the department of state registration of civil status acts.
Personally coordinate the details of the ceremony with the representatives of DRATSS and come at the chosen time and day to say "I do" and receive the marriage certificate.
It is not possible to sign up online. Marriage can be registered only in the DRATSS department in the personal presence of the bride and groom.