I would like to programmatically find out the balance of an ETH account.
How does a WebApp interact with an API? Totally new at this API thing so I don’t understand how exactly they work.
By ETH you are referring to ethereum, I guess?
Get an access key and more info about its api here:
https://etherscan.io/apis
Here a general example on how to use a webservice from xojo:
https://forum.xojo.com/46465-oauth-and-api/p1#p410425
Or read this Xojo blog articles:
https://blog.xojo.com/2018/09/26/web-services-xojo-web-at-your-service/