Answer
Enter unpaid days in the pay using the Unpaid leave type. The pay screen sets the rate to zero for Unpaid rows. If the employee takes a continuous period of unpaid leave longer than one week, the annual holidays anniversary or the average-weekly-earnings calculation may need special treatment.
Lightning Payroll does not infer every legal consequence from a zero-rate leave row. Decide whether the annual holiday anniversary moves out, or whether the anniversary stays the same and the averaging is adjusted, then record that decision.
After the decision is made, review the employee's start/anniversary details and any required manual adjustment under Employees >> Leave >> Leave Entitlement/Adjustments, using How is this balance calculated? to check the result. Keep a note explaining the decision.