You can manually disable it by clicking the X button, aldotcom. Let me discuss it further below.
If you meant the Suggested Transactions window on the invoice page, it will automatically populate if your customers have outstanding transactions that can be linked to your invoices, such as billable expenses or billable time. You can turn it off by clicking the X or back arrow button.
If you're referring to the transaction itself, you can follow what KimAnnVA outlined above to disable it.
However, please provide additional details if this isn't the case and if you mean something else regarding the suggested transactions.
Furthermore, you can explore these articles for comprehensive guidance on adding extra details or customizing your sales transactions: