yudi2021 - I am not 100% certain that I understand. I will do my best to reply; if I am misunderstanding you, please let me know, but if you can take your time and be very specific, I will be able to help you more.
First --- I understand that you cannot use jDownloader's extension. My suggestion for LinkClump was only a workaround.
Second --- After you configure LinkClump (to copy ONLY URL's) -- then you paste in the jDownloader "LinkGrabber" tab. Or, as an alternative, you can enable the "Clipboard Observer" (which will take the links directly, once you have copied them with LinkClump). The "Clipboard Observer" looks like a clipboard (notepad) with a small square in the bottom-left corner. It is at the top of the window, near the arrow up/down buttons.
If you can clarify the other points I will try to help further.