Bulk-add instructors from a spreadsheet or another system, then invite them separately.
On a phone it is "Import from CSV" in the overflow menu. Use "Download Template" if you want the exact column layout: Name, Email, Phone, Bio, Specialties.
Drag the CSV in or click "Choose file".
Tell Klasly which of your columns is the Name (one column, or First + Last) and which is the Email. Phone, Bio and Specialties are optional. A preview of the first five rows shows what will be imported, marking invalid emails in red.
Click "Import Instructors". The last step reports how many were imported, skipped and errored, with a row-by-row reason for anything that did not go through.