How to get center coordinates CSRNet model?

I am playing whit this interesting repo from github: GitHub - AndranikSargsyan/crowd-counting
Basically, it is a crowd counting algorithm build using CNN model called CSRNet. it is built using Pytorch.
I am just starting with pytorch and I cannot managed to get the coordinates or bounding boxes of the detections. I tried getting the coordinates using methods used to get bboxes from pretrained without success.
It gives as output a numpy array which is the heatmap.
How could I get the coordinates of each head detected? I would appreciate any help,