Can't Navigate Image Viewer

Hello.
I really like Directory Opus but it drives me bonkers that I can't use the left and right arrow keys to go to the next/previous images.
I found in some third party documentation (https://scribbleghost.net/2018/08/06/improving-the-viewer-in-directory-opus/#:~:text=Use%20the%20arrow%20keys%20to,are%20instead%20spacebar%20and%20backspace.) that says the keystrokes should be PgUp/PgDn or SPACE/BKSP. And it told me how to change the keys...
But those keystrokes do not work for me.
I counted, and there are 1,325,233 options in Directory Opus and I can't figure out which setting is causing the Image Viewer navigation to not work for me.
How can I get this fixed? Or how can I make DO launch the regular Windows picture viewer instead?
I made you a video to demonstrate the problem.
Loom | Free Screen & Video Recording Software | Loom
Thank you.
-Frustrated Mark

You can edit the viewer's hotkeys via Settings > Customize Toolbars > Keys:

It opens Windows picture viewer.

Change this setting to use dopus internal viewer.

2022-10-20_013232

Hello Leo and Hardkorn.
Thank you both for trying to help, however, your solutions are not working for me.
My Preferences were already set with the "Use Internal Picture Viewer" box checked, and as I showed in my first video, the pgup/pgdn buttons (or space/bksp) don't work to see the next/previous images.
I then tried deselecting that box, and the results are the same.
I made you another video to show you what is happening.

All I need is to be able to navigate from one image to the next from within the viewer, just like I am when launching the default image viewer from Windows Explorer. Any solution that results in that will work for me.
Any other ideas?
Thank you.
-M

At the start of your video, you've only turned on the Opus image viewer for unregistered image types.

Change that back to all recognized pictures if you want to use the Opus image viewer for everything.

Thank you, Leo. That did the trick. Now the DO viewer launches.
But I'm very curious...why is it that when the Windows viewer launches, I get no arrow keys or buttons?
As I showed you, that doesn't happen if I launch the viewer directly from Windows Explorer.
Thanks.
-Mark

The Windows image viewer is like that when launched by software other than File Explorer. From what I can tell, it seems to pull the file list out of Explorer using some undocumented method, and will not fall back on making a list of files in the same folder as the image when launched by other things. One of many reasons not to use it.

That worked. Thank you.