First, please make sure you enabled elasticsmile modules by reading this file "readme.txt"

https://drive.google.com/file/d/1FQDL6_ui40-DpWIr5_6sDwK10W912pQy/view?usp=sharing

Then, please refer this link to resolve this issue with your elasticsearch

https://stackoverflow.com/questions/42549586/elastic-search-give-an-error-no-alive-nodes-found-in-your-cluster

https://github.com/Smile-SA/elasticsuite/issues/1002