Amasty has a pretty good guide on configuring the Amasty Elasticsearch module that goes into many more module specific details that we wont touch on. Make sure you read it so you can get the most out of your configuration. We will cover the Cloudways specific pieces.
First navigation to Admin Panel > Stores > Configuration > Elastic Search > Catalog. Once here your settings will be:
Search Engine: Amasty Elasticsearch
Elasticsearch Server Hostname: The hostname of your Magento installation ie: your sites domain name or the default Cloudways hostname for your application.
Elasticsearch Server: 9200
Elasticsearch Index Prefix: magento2 (you can use whatever you want here but if you have multiple applications leveraging the same Elasticsearch instance, they all need to use unique prefixes).
Enable Elasticsearch HTTP Auth: No
Elasticsearch Server Timeout: 15
Once all the settings are in place, click Test Connection. If all went well, you will get a success message. If not, double check the previous steps to make sure the Elasticsearch service is running on the server and make sure that your hostname is correct.
Your Magento 2 site is now running Elasticsearch. Go give it a try and see how much better the search results are. Not only do they come back faster but it is much, much better at matching results. The Amasty module also gives you very granular control over what to search and how to search it so be sure to explore all that the module has to offer.