You don't really own your movie unless you've signed release forms with all of your actors. The actor release form basically transfers the rights to use any recordings or photos of the actor, as well as to distribute the movie and create promotional materials.
There are a few important elements which need to be covered in the actor release form:
Signing actor release forms online is much safer and easier than using traditional paper forms, especially if there are dozens of actors involved in the movie production. The information (including electronic signatures) won't get lost easily and can be transferred to third-party systems of your choice like Google Sheets or CRM systems.