Hello, I'm trying to set up a simple phone system as part of an interactive kids workshop for an art gallery.

I have acquired an old Panasonic KX-T30810 BE and I need to plug 4 phones into it, so that they can ring each other using an extension number and talk one-to-one.

It doesn't need to connect to the external phone system, it's just a local setup with the 4 phones.

Please could someone advise what cables I would use to plug the phones into the PBX? I know they're some kind of RJ cable, but I'm confused as to which connector I need... Sorry, I'm not very familiar with phone systems!

Many thanks,
Sam

Info about the PBX machine below:

https://www.voicesonic.com/panasonic/manuals/KX-T308_System_User_Guides/KX-T30810_Installation_Manual.pdf