Detecting a carrier

Hi list…
I’m implementing a FHSS and i have some trouble detecting my carriers, i
was triying to use the example to see how they do
but i’m still in the same trouble, does anyone knows a good reference or
have an explanation about how the detect the level of interference o
i can see mi carriers on the uhd_fft without any troubles, but how can i
extract that value? and use it for my demod process?