Yealink T23G - How to configure a desk phone on PABX?

[Dre84]

I'm looking at a new cloud based PABX but want to try out 3CX as the on-site server did not work at all for me.
I've now created one extension and the following link

https://www.3cx.com/sip-phones/yealink-t20p-t22p-t26p-t28p/#h.eu8l0fu5cgny

Does not tell you where you get the details for the IP phone to manual config the phone. The steps that are given is as follow: (see my comments in red)

1. Go to the “User” for which you want to add the DECT phone.
2. Go to the “IP Phone” tab. Click “Configure a phone” to add a phone.
3. Select the option “Outside the Office” and click “Next”. <- This option does not come up
4. Select “Normal Phone” and enable the option to “Configure your phone manually without provisioning <-- This option is greyed out

 

[SteveITS]

Do you have an SBC set up already?

 

[Dre84]

Hi, thanks for your reply, yes SBC has been added.