As it happens I was looking at this yesterday. Using Win10 64 bit / Gimp 2.10.30
You have the google-nik installer ? A bit of a monster 430 MB or so. Install to the default location, The Gimp plugins are set up for that location. You can test if the nik filters work. Each is a xxx.exe file. The Gimp plugins use the 64 bit versions. As a test drag-drop an image file onto the filter. example:
https://i.imgur.com/eHHyjB4.mp4Then you need the nik plugins from a Partha Gimp installation (or the link posted in the previous post). These go into the usual Gimp User plugins folder. Do not bother with the folders shown in the animation, put the python plugins straight in. The plugin makes a temporary file, sends it to the xxx.exe file just like above, Save the filter adjusted image and it gets sent back to Gimp.
Example:
https://i.imgur.com/W8uUfLg.mp4 I had to trim this down a little to fit it into 60 seconds but you should get the idea.