If you have previously added cash to your Freetrade account, you'll need to buzz in-app! Just head to the Portfolio tab > Profile icon > Contact us > Send us a message > My details > Bank account.
If you have never added cash to your Freetrade account, you can change your linked bank account in-app yourself. Simply head to the Account tab and enter your bank details.
Please bear in mind that your new linked bank will need to meet these requirements.