Hi @AmandaHeilman ...
Are you only wanting to share your Studio video with specific students in your course and not the entire class? I *think* that the students that you cannot find names for need to access the Studio library interface at least once so that their names would appear for you. Since Studio is a LTI tool built by Instructure, I *think* there is some kind of authentication method built into Studio. Have those students click on the "Studio" icon on the far left-hand side of the Canvas interface so they see their Studio library. If I recall correctly, if a user has never accessed the Studio interface before, they would be prompted with a screen to confirm their e-mail address.
I hope this will be of some help to all of you. Keep us posted...thanks!