Currently, the API supports querying by page ID: https://image-suggestion-api.wmcloud.org/?doc#/Image%20Suggestions/get_image_suggestions_v0__wiki___lang__pages
That works fine for production, but for local development it is not ideal, because if you want to retrieve a suggestion for an article in your local wiki, the local wiki page ID is unlikely to match the production wiki page ID.
For that reason, it would be nice to offer an option for querying by title(s). I don't know if this is already stored in the database, but you could call the Pages API https://api.wikimedia.org/wiki/API_reference/Core/Pages/Get_page with the title to get the ID. Note that the URL should use an environment variable for expansion, because in Kubernetes you wouldn't be able to make an HTTP request to api.wikimedia.org directly, it would have to go through a proxy. T276217: Use Envoy for making GET requests to lang.wikipedia.org/api.php is how we did this for research/mwaddlink, fwiw.