Should I go tightly coupled, with singleton, or loosely coupled, without a singleton? Azure Services, Xamarin Forms

Question

I am making a Xamarin Forms Cross platform app. I have been trying to figure out how to go about getting my app to integrate with the Azure Backend the best way. I have ran into a problem. It has been drilled into my head to try to build programs as loosely coupled as possible. But then I have been told to create my Azure Services class as a singleton to stop multiple creations and mucking up the backend connection

Since I cant use Interfaces with a singleton to make my app loosely coupled. I have to pick. I think I should go with interfaces, for loose coupling. But I don't know much about Backend development. Will creating multiple instances of my AzureServices Database class mess stuff up?

Thanks for any help.

Here is an example of the format of my AzureServices

namespace CoffeeCups
{

public class AzureService
{

public MobileServiceClient Client { get; set; } = null;

 IMobileServiceSyncTable<CupOfCoffee> coffeeTable;

public static bool UseAuth { get; set; } = false;

        public async Task Initialize()
        {
            if (Client?.SyncContext?.IsInitialized ?? false)
                return;


            var appUrl = "https://chattestjbapp.azurewebsites.net";


            //Create our client

            Client = new MobileServiceClient(appUrl);


            //InitialzeDatabase for path
            var path = "syncstore.db";
            path = Path.Combine(MobileServiceClient.DefaultDatabasePath, path);

            //setup our local sqlite store and intialize our table
            var store = new MobileServiceSQLiteStore(path);

            //Define table
            store.DefineTable<CupOfCoffee>();


            //Initialize SyncContext
            await Client.SyncContext.InitializeAsync(store);

            //Get our sync table that will call out to azure
            coffeeTable = Client.GetSyncTable<CupOfCoffee>();


        }

        public async Task SyncCoffee()
        {
            try
            {
                if (!CrossConnectivity.Current.IsConnected)
                    return;

                await coffeeTable.PullAsync("allCoffee", coffeeTable.CreateQuery());

                await Client.SyncContext.PushAsync();
            }
            catch (Exception ex)
            {
                Debug.WriteLine("Unable to sync coffees, that is alright as we have offline capabilities: " + ex);
            }

        }

        public async Task<IEnumerable<CupOfCoffee>> GetCoffees()
        {
            //Initialize & Sync
            await Initialize();
            await SyncCoffee();

            return await coffeeTable.OrderBy(c => c.DateUtc).ToEnumerableAsync(); ;

        }

        public async Task<CupOfCoffee> AddCoffee(bool atHome, string location)
        {
            await Initialize();

            var coffee = new CupOfCoffee
            {
                DateUtc = DateTime.UtcNow,
                MadeAtHome = atHome,
                OS = Device.RuntimePlatform,
                Location = location ?? string.Empty
            };

            await coffeeTable.InsertAsync(coffee);

            await SyncCoffee();
            //return coffee
            return coffee;
        }



        public async Task<bool> LoginAsync()
        {

            await Initialize();

            var provider = MobileServiceAuthenticationProvider.Twitter;
            var uriScheme = "coffeecups";



            var user = await Client.LoginAsync(Forms.Context, provider, uriScheme);


            if (user == null)
            {
                Settings.AuthToken = string.Empty;
                Settings.UserId = string.Empty;
                Device.BeginInvokeOnMainThread(async () =>
                {
                    await App.Current.MainPage.DisplayAlert("Login Error", "Unable to login, please try again", "OK");
                });
                return false;
            }
            else
            {
                Settings.AuthToken = user.MobileServiceAuthenticationToken;
                Settings.UserId = user.UserId;
            }

            return true;
        }    
    }
}