You can find the history of all your dividend payments in your account statement.
First, you need to access your Account Statement. You can find how to do it here.
Once you open the Statement, you will see the Dividends section. It shows all dividend payments - credited or debited - in the selected period of time.
You can identify each dividend payment by date of payment, instrument name, and position ID, type of asset, and ISIN code.
Each payment is shown as the net amount in USD, along with the amount of withholding tax applied in USD, and the withholding tax rate.