I want to do a demo for one of our clients about SharePoint online. now our customer already have a free basic office 365 with one admin user. so I have created some site collections with lists and libraries. then inside my windows 7 machine and using visual studio 2015 professional, I develop a demo remote event receiver, using provider hosted add-in. Now as per my reading, hosting a remote event receiver can be done inside :-

1. any windows server which is exposed to the internet.
2. or inside Azure service.

now I want to chose the second option, as we are proposing our customers to chose cloud solutions. but my question is how I can host my remote event receiver inside Azure for demo purposes? I do not want to buy anything at this stage, so is there a way to host my remote event receiver on a trial azure for a trial period (2 weeks is more than enough)? If this is not possible then where I can host my remote event receiver for free to complete my demo?

Thank in advance for nay help on this. but I am really having troubles in knowing if I can host my remote event reliever on a trial azure or trial windows server to complete my demo with our customer?