Unity app crashes when built for iOS with camera enabled

Question

I have an app which uses zxing to scan qr codes in the app. However when I build the app with these scripts in the scene the app crashes on startup. I thought it was something in the Awake() or Start() but I've wrapped those methods in a try catch, and even then I'm not getting any errors, and it doesn't crash on android and in the editor.

I don't have access to a Mac, and am using Unity Cloud Build to build it.

I also don't know how to enable permissions, I thought I did when creating the .p12 file, but I've also found that there's an info.plist file that I have to request permissions with.

Prior research I found this Unity Question about adding items to the Xcode project but not only did including the xcodeapi give me errors, but the using statements didn't work.

There are two scripts

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System;

public class WebCamController : MonoBehaviour {

    public int desiredWidth = 1280;
    public int desiredHeight = 720;
    public int desiredFPS = 60;
    public RawImage output;
    [HideInInspector]
    public WebCamTexture webcamTexture;

    void Start ()
    {
        webcamTexture = new WebCamTexture(desiredWidth, desiredHeight, desiredFPS);
        output.texture = webcamTexture;
        Play();
    }
    public void Play()
    {
        webcamTexture.Play();
    }
    public void Pause()
    {
        webcamTexture.Stop();
    }

}

and

using UnityEngine;
using System.Collections;

using ZXing;
using ZXing.QrCode;
using ZXing.Common;
using System;

public class CodeScanner : MonoBehaviour {
    private static CodeScanner _instance;
    public static CodeScanner Instance
    {
        get
        {
            if(null == _instance)
            {
                Debug.Log("Code Scanner Instance not found");
            }
            return _instance;
        }
    }

    [Header("References")]
    public WebCamController wcc;

    [Header("Properties")]
    private BarcodeReader codeScanner;
    private string lastScanned = "";

    public delegate void Found(string text, string type);
    public event Found OnCodeScanned;
    private bool active;

    public void Awake()
    {
        _instance = this;
    }

    void Start () {
        codeScanner = new BarcodeReader();
        StartCoroutine(ReadCode());
        wcc.Play();
    }

    IEnumerator ReadCode()
    {
        while (active)
        {
            try
            {
                var data = codeScanner.Decode(wcc.webcamTexture.GetPixels32(), wcc.webcamTexture.width, wcc.webcamTexture.height);
                if (data != null)
                {
                    //if (data.Text != lastScanned)
                    //{
                    OnCodeScanned(data.Text, data.BarcodeFormat.ToString());
                    //}
                    lastScanned = data.Text;
                }
            }
            catch(Exception e)
            {

            }
            yield return new WaitForSeconds(1.0f);
        }
    }


    public void Activate()
    {
        wcc.Play();
        active = true;
        StartCoroutine(ReadCode());
    }

    public void Stop()
    {
        active = false;
        wcc.Pause();
    }
}

My device is added properly to the .p12 certificate I can compile and run the program without these scripts in the scene.