How can i get class_id in the file?

How can i dump in the file class_id or category_id of the coco image , if i’m using mmdetection. Should i change in class aips/ or datasets/ or the config file for the model ? as what i’m got this array for every image

[3.41282135e+02, 2.03359509e+01, 4.95520966e+02, 3.14121826e+02,

and i need the structure of the file contains


and sorry if the post in not appropriate here if someone can help or guide me i will appreciate that