In the past, Google allotted a quota of X number of index requests per month. But evidently, the system has changed, and there is no longer any quota listed when hovering over the two crawl options:
Crawl only this url
Crawl this url & its direct links
The solution is you can still submit 9-10 URLs per 24-hour period and per crawling option (“Crawl only this URL” or “Crawl this URL and its direct links”), for a total of 18-20 requests per day.