We typically don’t recommend using a managed server configuration during development and testing. Unfortunately I have not worked with this type of setup. You can give the below options a try and see if it works.
Under the Weblogic connector, under the Launch node, there is a radio button for making the server as “managed” (This server is externally managed). Try that and see if it works.
Alternatively you can use the Create Launch Configuration button on the Launch page to create a custom launch config (you can get to it from your normal Run or Debug menus) and then to edit that configuration to see what arguments are being used to launch it and possibly modify the launch arguments to see if you can get that config to launch. If you can, then you can use that information to config the normal connector with optional JDK or WL start up args.