Hi LouRee,
You will need to log into your personal tax account and open your tax return to amend it.
After the calculation, there is an option to reduce the payments on account, you can reduce them to £0.00 if you want.
As you are no longer resident in the UK, it may be better that you contact our self assesment helpline on 0300 200 3310 or contact our webchat facility at
Contact HMRC,
to ensure your records are updated and if a tax return is no longer required, to ensure the self assessment record is made dormant.
Thank you.