As a comparison, you can put the query string from an api.php request into the hashtag for Special:ApISandbox and it will prefill the latter's form, i.e. take
and make the URL
- https://en.wikipedia.org/wiki/Special:ApiSandbox#action=query&prop=pageimages|pageterms&titles=Albert Einstein
allowing T89680: Template:ApiEx on mw.org should have a link to "[view in ApiSandbox]".. I think we could build a similar Template:RestApiEx for RESTBase example requests on mw.org.