I'd be glad to provide you the steps in restoring your 2020 information in QuickBooks Self-Employed.
Once you delete an account in QuickBooks Self-Employed, all transactions prior to the deletion will be eliminated permanently. To restore your information from 2020, you'll need to reconnect your bank account so you can download those transactions.
Go to the Settings ⚙ icon and select Bank accounts.
Click + Connect another account.
In the search box, enter the name of the bank and account type, i.e Lloyds Bank Business, Lloyds Bank Personal, or Lloyds Bank Commercial.
Follow the on-screen instructions to connect your account.