GIMP 2.10 style unsharp mask with OpenCV and C++

Using the following GIMP filter (unsharp mask) for bunch of images:

filters > enhance > unsharp mask with values of radius = 6.8, amount = 2.69, threshold = 0.

Need to make the same with Open CV functions, using C++ (Ubuntu 20).

Tried open cv Gaussian function and few cvt conversions, failed to get result needed