System.InvalidOperationException: 'You must call Xamarin.Forms.Forms.Init(); prior to using this property.'

Question

I created a new UWP app, something I've never done before, and copy and pasted a bunch of code from another Xamarin Forms project, code that did work there. Now I run into the error:

System.InvalidOperationException: 'You must call Xamarin.Forms.Forms.Init(); prior to using this property.

"this property" being a chuck of code meant to create a "refresh rate" so that I can create movement of SkiaSharp graphics: (if theres a better way to do this please let me know)

Device.StartTimer(TimeSpan.FromMilliseconds(1), () =>
            {
                canvasView.Invalidate();
                return true;
            });

I don't necessarily just want the code to make this work but I genuinely would like to understand what's happening. I can't just insert Forms.Init(); into my code because that requires parameters, but I don't know what parameters to feed into it. I don't necessarily just want the code to make this work but I genuinely would like to understand what's happening. Any help is appreciated.

My code:

using RPS_Sim;
using RPS_Sim.Objects;
using SkiaSharp;
using SkiaSharp.Views.UWP;
using System;
using System.Collections.Generic;
using Xamarin.Forms;

namespace RPS_Sim
{
    //Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    public partial class MainPage
    {

        int speed = 1, size = 50;
        PosMov posMov;
        Rock rock;
        Paper paper;
        Scissors scissor;
        List<Object> Objects;


        int w, h;
        public MainPage()
        {
            DependencyService.Register<MainPage>();
            InitializeComponent();
           
            Device.StartTimer(TimeSpan.FromMilliseconds(1), () =>
            {
                canvasView.Invalidate();
                return true;
            });

            posMov = new PosMov(0, 0, speed, size);

            rock = new Rock(posMov.x, posMov.y, posMov.speed, posMov.size);
            paper = new Paper(posMov.x, posMov.y, posMov.speed, posMov.size);
            scissor = new Scissors(posMov.x, posMov.y, posMov.speed, posMov.size);

            Objects = new List<Object>();


            Objects.Add(rock);
            Objects.Add(paper);
            Objects.Add(scissor);

            foreach (var O in Objects)
            {
                O.Randomize(1);
            }
        }
        private void canvasView_PaintSurface(object sender, SKPaintSurfaceEventArgs e)//, MouseButtonEventArgs mouse)            //put all realtime events here
        {
            
            SKSurface surface = e.Surface;
            SKCanvas canvas = surface.Canvas;
            canvas.Clear(SKColors.White);
            w = e.Info.Width / 2;
            h = e.Info.Height / 2;
            canvas.Translate(w, h);

            /*foreach (var O in Objects) 
            {
                O.Update(canvas, w, h);
            }*/

            rock.Update(canvas, w, h);
            paper.Update(canvas, w, h);
            scissor.Update(canvas, w, h);
        }

    }
}