Please describe Custom keyboard settings for Viber bot

Hello.
I will try to explain with an example (all names are fictitious).
1. You create an initial setting (greeting) in which you do not specify the text of the incoming message, but indicate the response, for example "Hi. What do you want?"
You also create 2 "I want pizza" buttons that will send the text "I want pizza" and "I want a burger", the actions of which are to send the same text.
2. You create a setting with the text of the incoming message "I want pizza", where you indicate the answer "What kind of pizza do you want?", check the box that this is a question.
3. Next, you create the setting "Where to deliver the pizza?", set that this is a question and choose that you need to send this question after answering the question from step 2
Further, in this setting, you specify a GET request link (with parameters in the link) that must be sent after answering this question (for example, in the REST API for adding an order). How to use the answer variables for the question is indicated in the tooltip next to the field name (question mark icon) - for example, if the setting is the question "What kind of pizza do you want?" has id=2 - then you need to use the variable [var2]
Also, in the case of specifying a link, you must specify the text that must be sent in case of successful or erroneous execution of the request.
PS: We plan to implement a video tutorial on how to use this functionality soon.