You will need to go through HMRC to reclaim the unused employer allowance and utilise the Basic PAYE Tools, Ken. Let me discuss this further with you.
Based on the information you've provided, it appears that you activated the employer allowance claim late, which is why you cannot claim the full amount. Therefore, you must reclaim the employer allowance using the Basic PAYE Tools. For more information, please refer to this article: Submit an FPS to HMRC in QuickBooks Online Standard Payroll.
In addition, you can check this article to view all your previous FPS and EPS submissions from the Payroll Tax Centre: View submitted FPS and EPS filings in QuickBooks Online Standard Payroll.
If you have questions about submitting the EPS or need further assistance with QuickBooks, I'm here to help in any way I can.
