Before searching documents, you must index the documents via RChilli Search and Match index API using your index key. The searching is always done on the documents that you have indexed. For more details on indexing the documents, see Parse and Index.
Simple Search API searches the document based on the entities on the documents like skill, employer name, job profile, degree, experience, and location. If your indexed documents do not have the entity you are searching for, then no result will be displayed.
Also, Simple Search API does not support free-text searching; the search keyword must always contain at least one entity to get a result. To do free-text searching, see Free Text Search.