Custom Dynamic DNS with UniFi Dream Machine Pro

I recently bought a UniFi Dream Machine Pro (UDM Pro). I did a ton of research before getting it and saw Dynamic DNS (DDNS) support. But it only supported a hand full of DDNS providers. My domains are in AWS Route53, and I did not want to pay premium pricing for the supported DDNS providers. So I embarked on a journey to create a personal provider to update a subdomain hosted in AWS Route53.