Per Derek Law's old answer (Trail version of ArcGIS server installer), esri was (not sure if they still are) providing evaluation windows for ArcGIS Enterprise using AWS. However, that was three years ago when the deployment was still rather new, but it can't hurt to visit their site (ArcGIS Enterprise | Enterprise GIS Mapping Platform) and try and start a chat with the customer service rep to see what can be worked out.
If you don't mind me asking, what are you planning to do with the ArcGIS Enterprise license? Trying to learn the software? Create Web Map / Apps? Seeing if it works for your business? Knowing the why might help get you a solution