(macbook 2020) I cant access the settings that allows my downloaded dynamic wallpaper to be dynamic because the fitting settings for the wallpaper is sitting right over it

Did you try the instructions from dynamicwallpaperclub.com?

Using one of our wallpapers on macOS Catalina

Due to a bug in macOS Catalina, installing dynamic wallpapers is a little bit different and we hope to see it fixed in the upcoming macOS Big Sur.

Thanks to our community there is a solution that seems to work most of the times:

• Go to "System Preferences" → "Desktop & Screen Saver"
• Select one of the official wallpapers shipped with macOS like "Catalina" and set it to "Dynamic"
• Open Finder and look for the wallpaper you downloaded on dynamicwallpaper.club
• Right click on the file and select "Services" → "Set Desktop Picture"

You have to follow the instructions exactly. Notably, it doesn't say to close System Preferences after setting the stock dynamic wallpaper to Dynamic, and if you do close it, and it was set to Light (Still) or Dark (Still), when you set the dynamic wallpaper as the desktop in Finder, it will be set to Light (Still) or Dark (Still) and when you go back it will be the overlaid setting you see.

To start over, set the desktop to any still image, close and reopen System Preferences > Desktop & Screen Saver, set to the dynamic Catalina, switch the dropdown to Dynamic, then with the preference pane open, go to Finder and secondary-click on the wallpaper .heic file, then select "Services" → "Set Desktop Picture". Then you can close System Preferences and you'll have your custom dynamic wallpaper.

I suspect a screenshot would help understand your issue.

https://support.apple.com/en-us/HT201361

(Post it using the 'picture' icon below the post entry window, second from the right).

Use this to attach the image.