[Koha] authority control

I'm using authority control of the 100 fields in MARC21. I'm importing records from the Library of Congress. As I do that I'm importing authority records and linking them to records. I now have a piece where there is no authority record for the author in LC authorities. I try to just enter the name as it appears on the title page and Koha does not let me enter anything. Is there no way to enter text on an authority linked field on my own? Will I have to create my own authority record for each of these names? --Jason