How to input 'Total adjustments due to Marriage Allowance' and 'HMRC Refund' in self-assessment

I am PAYE but I did not claim the Marriage Allowance from my wife at the beginning. Therefore, there is a total adjustments to be deducted in the 2022-2023 tax year is £508.05 (due to the Marriage Allowance for 2022-2023 tax year and 2021-2022 tax year). Finally, HMRC owes me Income Tax (2022-2023 tax year) £178.25 which was refunded to me by cheque. During the 2022-2023 tax year, I earned £1461.61 untaxed interests in UK banks. The extra tax I should pay for the untaxed interests should be around £92. However, I cannot get this figure in the draft self-assessment. Where should I input the below items in the self-assessment? -Total adjustments to be deducted (£508.05) -HMRC owes me Income Tax (£178.25)

Hi felixk,
To have Marriage Allowance applied to your 21/22 and and 22/23 statements, you and your partner should first apply for Marriage Allowance via www.gov.uk/marriage-allowance. When you then submit your returns for these years, the transfer should show on each individual calculation. If your 22/23 income tax refund was repaid to you before you began filing Self Assessment, you should include the amount refunded on the page titled 'Tax refunded or Set Off'. Untaxed Interest should be declared by clicking 'Yes' to the question 'Did you receive any interest' on the 'Tailor Your Return' page 2 of 3, then entering the amount received under 'Untaxed UK Interest etc'
Thank you.

Thank you for the reply and I followed your advice. For 'Tax refunded or Set Off', I input £178.25 that I got the refund. For Untaxed Interest, I input £1461.61. The total tax due is £600, which cancel out the £508 Marriage Allowance for 2022-2023 tax year and 2021-2022 tax year. I try to input £508 into 'Adjustments to tax due'>'Decrease in tax due because of adjustments to an earlier year'. This will make the total tax due reasonable. However, there is a problem. 'You cannot enter an amount for 'Decrease in tax due because of adjustments to an earlier year' since your return does not contain any adjustments which would affect the tax due for a previous year, Please amend.' Please help.

Hi felixk,
If you are in receipt of the marriage allowance transfer you do not enter anything on your Self Assessment tax return.
Once processed your tax return will be amended to include the marriage allowance transfer which will then amend the calculation. 
Thank you.