How do I add module position in the main body block of T3b3 Blank, the module should be in between sidebar-1 and sidebar-2 above the "message" or "content"?

Hello....,
I am sorry to ask this question that may sound simple for you, but still not clear enough to me after I read the documentation.
I want to add module position in main body block, the module should be in between sidebar-1 and sidebar-2 above the "message" or "content".

Actually the module position should like "position-3" of default "protostar template" of joomla 3.x.

Where do i put the div and what class or id tag should i use?

Thank you and Best regards,
Bun