Pin number

Not sure what you are referring to as PIN no.

Each license holder has a personal ID for his meetings and can setup a passcode for it. This is setup as per the instructions here: https://support.zoom.us/hc/en-us/articles/203276937-Using-Personal-Meeting-ID-PMI-

The PIN (For checking VM from an outside phone and/or hoteling into a common area phone) can be set in the individual account profile. It's located by navigating to Personal> Phone> Settings and then scrolling down to the "desk phone" area. That's where the PIN Code field resides. 

Seeking an instruction to create a PIN for login to ZOOM.