Adjusting Opening Balances - Sage Accounting

Good day,

I have taken over my company's accounts and our previous team left the accounts in a mess.

I need to adjust the ledger accounts especially the balance sheet accounts at the end of FY22 so FY23 has clean data.

I opened the appropriate VAT period, I also dont have a lockdown period but it says cannot adjust due to it being in a closed period.

the opening balances under company settings doesnt cut it for me as some accounts will be adjusted at a different date.

is imports via CSV my only bet for each account ?