Sending a message using SiriKit

Question

I already have a messaging app, and I would like to implement Siri to send a message. I have added the Intents extension and everything, I am just having problems figuring out how to send the message. I have tried to use the same function for sending the messages in the ChatVC, and copy and paste that into the IntentHandler.swift file but it gives me a bunch of compiler errors. Is there some type of framework that I should use to communicate to the app to do it or something? I am using Firebase as my database if that information is needed.

Updated code:
note, this code is the send function that I have when a user sends a normal message, and this is what I copied and pasted into the SiriIntent...

 func handle(sendMessage intent: INSendMessageIntent, completion: @escaping (INSendMessageIntentResponse) -> Void) {
    // Implement your application logic to send a message here.

    sendMessage()

    let userActivity = NSUserActivity(activityType: NSStringFromClass(INSendMessageIntent.self))
    let response = INSendMessageIntentResponse(code: .success, userActivity: userActivity)
    completion(response)
}

func sendMessage(text: String?, date: Date, picture: UIImage?, location: String?, video: NSURL?, audio: String?) {

    var outgoingMessage: OutgoingMessage?

if let text = text {      

        let encryptedText = EncryptText(chatRoomID: chatRoomId, string: text)

        outgoingMessage = OutgoingMessage(message: encryptedText, senderId: FUser.currentUser()!.objectId, senderName: FUser.currentUser()!.firstname, date: date, status: kDELIVERED, type: kTEXT)
    }
  }

Thank you so much for all the help!