duplicate your image in the layer dialog
Mode linear burn or multiply, then "new from Visible"
you can add a gradient mask id you want to fine tune, play with curves etc...
the xcf
https://ufile.io/r7tlzc3l
Mode linear burn or multiply, then "new from Visible"
you can add a gradient mask id you want to fine tune, play with curves etc...
the xcf
https://ufile.io/r7tlzc3l