Personal communication by face-to-face, telephone or online (such as Skype) methods can be referenced as follows.
You will need:
Sender/speaker/author’s Surname, Initials. (Year of communication) Medium of conversation with Receiver of communication, Day/month of communication.
Horwood, W. (2021) Conversation with John Smith, 9 January.
In-text citation: (Horwood, 2021)