im not sure you can turn off the text ability from a ringcentral number, but maybe take a look through the programming and see what types of roles you can make and see what features you can or can not give employees access to. this way your employees cant physically text out to as customer from your RingCentral numbers at least.
I not really looking to stop an employe's ability to text anyone. Just certain customers that would opt into receiving messages from us and then at a time that the customer would no longer want to receive messages be able to stop. For example I get texts all the time that say reply "stop" to stop receiving messages.