ios, swift - help with arranging some bluetooth requirements

i have a working program corresponding with these needed requirements: iOS app with six buttons - buttons are enabled if the central is subscribed to the characteristic - mutable service and characteristic are used. The characteristic will allow central devices to subscribe -Your device is assigned as a peripheral device that connects to my central via Core Bluetooth - Each button much correspond to a value that your characteristic changes. The value here is a string of the numeric values 1-6. EX: let value = "1"