showing pics on my tv using my MacBook Pro

I am trying to figure out a way to show my pictures on my tv using either my Apple TV (3rd gen) or my Roku Express +. or just AirPlay I have tried the Roku Media Player, AirPlay, screen mirroring. i haven’t found any apps that do this (that also don’t restrict me to a slideshow or playlist.) Also everything I have tried have very clunky means or moving from one pic or folder to another. 

Is there an OSX app that will do this and not:

- blacken my MBP (MacBook Pro, running Big Sur) screen when it goes full screen or uses Airplay?

- not restrict me to playlist or slideshow to see the pics?

Using the Finder is too many steps and it blackens the MBP screen when using full screen or Airplay.

Using screen mirroring and the tv as a separate display blacken the MBP screen. I NEVER want my MBP screen blackened. I want to choose what pics I want to see on the tv on my MBP. 

I don’t like how Photos (and Apple TV) make me use a slideshow or screensaver. I want to look at whatever pics I want to look at, not have to set up an app that makes me create a slideshow or playlist. 

The freedom to look at this or that as easily as choosing what folder they are in is what I want. Very little other busywork. I want to freely move around folders and display whatever pics I want. It has to be easy.

I haven’t found any apps to do this yet. None feature Airplay as that seems to be only a feature that video players use. I don’t understand that. Photos would almost work for me if 1) it didn’t black out my MBP when going full screen or 2) didn’t have a white background for the area of the screen that isn’t the picture. If if had an extension that would display pics on the tv as I like or had a black background option, that would work for me. (I see I can make my MBP use Dark Mode but I don’t want that on my MBP, only the app so it isn’t distracting when looked at on the tv. 

Any help would be appreciated. Thanks.