In the feature list(https://www.3cx.com/ordering/pricing/), could you please tell me what is the function Escalate Chat to Call? because in the standard edition, we still can call each other when we are chatting.
This is referring to the ability to start a Live Chat session with text only, but them also allow the web visitor to escalate it to a voice/video call.
This feature was implemented as a 'PRO' feature, however you are right, currently it is possible also with STD. This may change at some point though, so if you want this for your customers, you should consider getting a 'PRO', not a STD edition licence, to ensure they don't lose it in a future software update.
