I cannot seem to step into drop-down menus within my iFrame on page, please help?

I followed the tutorial/video on how to set-up the test objects for identifying my iframe but now I wonder if this is right because I cannot verify test or select dro-down menu items within the iframe.

Which browser are you using?

Chrome? then you should check the following post:

Firefox? then you should check the following post:

I am using Chrome for this and did follow the Katalon video on how to do this with no luck.