We need to know a lot more about your computer, hardware and software, if we are to have any chance of attempting to help you with this problem. Please read this post and give us ALL the information requested there, especially about your audio interface and how, exactly, you are connecting the video player to your computer.
I have the same issue "No audio device found..." attempting to screen record on my Panasonic CF-53 laptop.
Windows sound settings doesn't show mic input but shouldn't I be able to record from with internal "backloop" (sorry I do not know the terminology). Years ago I did it with Camtasia on a old computer without any problems.
Processor Intel(R) Core(TM) i5-3340M CPU @ 2.70GHz 2.70 GHz Installed RAM 16.0 GB (15.9 GB usable) System type 64-bit operating system, x64-based processor Pen and touch Single touch support
Edition Windows 10 Pro Version 20H2 OS build 19042.928 Experience Windows Feature Experience Pack 120.2212.551.0
shouldn't I be able to record from with internal "backloop"
Do you mean you want to record what used to be called "What you hear" or "Stereo Mix"?
If so, due to pressure from the RIAA (Record Industries Association America), Microsoft have tended to remove or hide the facility. (The RIAA believe that computer owners use that facility to create "illegal" clones of CDs etc.)
It is sometimes possible to restore this but it will very much depend on finding the appropriate settings for your computer.
Yes the default settings in Win 10 for the Stereo Mix is now 'Off' and needs to be reactivated as shown in my images above. Without that activation is is impossible for some applications to make use of the Realtek sound mixer.
To see what is going on or to sort out possible sound problems you can use Windows Settings to see what app is using what resources and alternatives that could be selected and tried if not working, although the 'Default' shown setting never mentions which one is currently in use and normally doesn't need changing.
In addition to the checks above, in the Windows settings, Privacy option for the Microphone and Camera settings ensure that the options Allow desktop apps to access your microphone (camera) are both turned on.
You are looking in the wrong place for the Stereo Mixer.
To get to the correct dialog - open the location Ray has given and select Sound Control Panel under Related Settings on the right of the page.
In the Sound settings dialog select the Recording tab where you should see the Stereo mixer is disabled - if you cannot see it right click one of the items you can see and click the Show disabled devices option - right click the Stereo mixer and enable it and set it as Default device as shown below.
Looking at the Panasonic website for drivers, you may be correct and not have the hardware to achieve recording using a stereo mix within the laptop or have a virtual mic. There appears to be nine versions of your laptop so I think you need help now from Panasonic to see what is possible.
According to the specs for the CF53, and is seen the images you posted, the audio chipset is an Intel High Definition audio chipset.
Check if there are newer versions of the drivers available from Panasonic - not Microsoft Windows provided drivers which can be 'dumbed down' versions not providing all features - I had this issue with my sound card.