I actually found out that I was wrongly logged into the incorrect twitch login when testing, resulting in the Auth token not working properly. It works perfectly now. The issue I am having now though is when creating new redemptions the images are not showing up.
{
title: 'Test',
cost: 50,
background_color: "#00E5CB",
prompt: "You bought something",
image: {
url_1x: 'https://static-cdn.jtvnw.net/custom-reward-images/69905566/08fd74e8-7e1e-4861-b4d4-1ff2dd938c9a/61f01a02-3833-4f32-8a29-a97760ebedbc/custom-1.png',
url_2x: 'https://static-cdn.jtvnw.net/custom-reward-images/69905566/08fd74e8-7e1e-4861-b4d4-1ff2dd938c9a/61f01a02-3833-4f32-8a29-a97760ebedbc/custom-2.png',
url_4x: 'https://static-cdn.jtvnw.net/custom-reward-images/69905566/08fd74e8-7e1e-4861-b4d4-1ff2dd938c9a/61f01a02-3833-4f32-8a29-a97760ebedbc/custom-4.png'
},
background_color: '#1F69FF',
},