Ability to Program 3rd party Numbers on Soft Key (blf key)

On my Cisco 8861, I am unable to program the softkeys to dial out to any number outside of a ringcentral extension assigned to us. If I want to program a speed dial to a customer, or assign an intercom to an extension as a speedial(blf key) it is currently not allowed. I am not sure why a simple feature like this is not allowed on Ring Central. It would make business operations so much easier to utilize the 5 soft keys that are lying dormant to be able to dial out to our customers, etc.