In California, every county's superior court chooses how and when to implement electronic court filing and for which case types.
Self-represented litigants are exempt from California Rule of Court 2.253, covering mandatory electronic court filing. So even where eFiling is required for other case types, self-represented litigants will still be allowed to file documents in paper form at the court. However, if self-reps choose to electronically file, then they are allowed to wherever eFiling has been enabled for Small Claims or other case types as applicable.
Review the list of current eFiling counties to see where eFiling is available for Small Claims cases. eFiling in California>>