Gurgling Noise from Kitchen Sink

After each drainage, the gurgling noise comes out.
Used Kinetic Auger (7m ) long and found no blockage
Suspected Air Vent pipe ( Stink Pipe) is blocked.

Found one on roof and one in garden, not sure which one.
How to know if the air vent pipe is blocked ?
What else can I do?

someone recommended to install the Deks Air Admittance Valve under my sink around the P-Trap....was not sure if this is the right thing

Seal each pipe in turn, and then both, and test to see if that causes any change. If it does, that could narrow down your culprit.

I doubt it's the vent pipes.
The blockage will be in the drains.
7 metres isn't really long enough to try and clear blockages. Get a drain cleaning specialist out. They use high pressure drain cleaners and cameras to inspect all the drains.
We had a similar issue at our rental. I watched him work and saw the before and after pictures. It only took 30min and at least the camera verifies what the actual issue is

Thank you for your advice.

Thank you very much..
Appreciate all your advice