If you are running the cloud/online version of Microsoft Dynamics 365 Business Central, you can find and install the Direct Banking app in Microsoft AppSource.

If Direct Banking is already installed and an update is available you can update the app in the Business Central Administration Center.
The Administration Center can be accessed with the following URL: https://businesscentral.dynamics.com/[TENANT_ID]/admin
Replace [TENANT_ID] with the tenant ID of your Business Central.

An overview of the available environments for your tenant will be displayed.
Select the environment where you want to update Direct Banking.

On the Environment page, choose Apps to go to the App Management page.

On the App Management page you can see the installed version and latest available version for your apps.
If an update is available it should be possible to click the Install Update action.
You are however advised to first test newer versions in a sandbox before applying them into production.
The application update will now be scheduled and processed in the background.