Adding custom class annotations to the existing Coco annotations

[Ekta246]

Hi,

I understand how can I parse/filter only the categories out of the 80 categories of Coco dataset I want. Like for example if I want 3 categories say cat, dog, potted plant.
What if I want to add the custom class of my dataset to these selected 3 categories. Also, I have my custom dataset of 1 class in coco json format already.
It would be challenging to add/merge annotations manually in the existing coco dataset.
Is that any way that I can merge the custom class with the wanted categories of Coco like I mentioned above?

I need help
TIA