Open the text version in your banner set and click edit.
Set "Target" to "Landing page". Then click "Select landing page" to select which landing page you want to connect to this banner set.
Done, I have now selected "Sound of Sweden" as my landing page and the English version. You can now edit your other versions in this banner set and connect them to other language versions of the same landing page.
Last but not least, if you wish to have a query sting appended to the target URL they can be added here in the input field "Query". This is mainly used for adding UTM parameters to your target URLs.