In order to enable both CSAT or NPS, or to enable both of them, you need to open your bot, and navigate to the Collecting User Feedback Skillset.
In this Skillset, open the Register "Yes" or "No" Code Step, and open the Code editor.
In the Code Editor, you need to set both the flags IS_CSAT_ENABLED and IS_NPS_ENABLED to True, and then you will have enabled both Feedback mechanisms for your bot.
Note:
Enabling both CSAT and NPS means that 50% of the time CSAT Feedback will be asked, and 50% of the time NPS will be asked, and moreover, this is a coin-flip logic. So it might not always be exact 50-50%.