Let me explain why the unrealised gain or loss is unavailable in the trial balance.
The Profit and Loss show your income, expenses, and net income (profit or loss) totals. Using this report, you'll be able to see and evaluate the progress of your business. While the Trial balance and Chart of Accounts only summarizes the debit and credit balances.
Additionally, we're unable to add the unrealised gain or loss in the Trial balance and Chart of Accounts as this is working as designed.
I've added some links you can check. These will show you the list of available reports and how to customise them: