As of the new Financial Tax Year (2021 - 2022), HMRC will decommission the ability to submit previous year amendments through EYU. Instead, they will be done through YEA FPS (Year End Amendment - FPS)
Navigate to: Payroll > Select Client/Employer > Submissions > YEA-FPS
Click the +Submit YEA FPS button as highlighted above to begin, then input your amended values where applicable in the various tabs. Once done, proceed with submission by clicking the HMRC Submit button.
Once submitted you can download HMRC's response using the action drop-down menu