Screenshot program problem with imgur

I have an imgur acc. When i logged in using firefox, i can upload and whatever in it works.

How ever when i do screenshot using “print screen” it does not work.

OK, to make sure my question is valid , i tried both “print whole screen” and “print rectangular area” 2 types.
The conclusion is : “print whole screen” able to share to imgur - no problem
However “print rectangular area” failed to share to imgur everytime, at least the time I am trying it.
I have being having this problem for quite a few weeks i think… even before i posted the previous post regarding this issue. (i have no time , hence chuck it aside)
Please look into photos for detail.

Print “rectangular area” (failed):
20201004_134217
select rectangular area to be print screened.

20201004_134235
see i selected share to imgur.

20201004_134325
Then it failed to upload to imgur, but it open gwenview (instead of showing me the url)

This is Print whole screen and share to imgur - working fine…
20201004_134430

20201004_134447
See! with a successful uploading to imgur, it provides the link to the img.

I also tried to search for the location where i can let the os signed imgur (it is common sense to need to sign in to use the service, however in this case there is no sign in?! )
Screenshot_20201004_153123
I don’t know where to sign in in this Endea linux… there is an “online accounts” when i use Krunner to search for “account”, however there is “NO accounts added yet” inside it. Since i can share whole screenshot to imgur, surely to register or signin imgur is not nessacery, else both (print whole screen and print rectangular area) should not work altogether already.