There are exactly two ways to request a recrawl, and neither guarantees speed.
URL Inspection tool
For individual URLs. Inspect the URL in Search Console and choose “Request Indexing”. There is a daily quota, and repeated requests for the same URL do not move it up the queue.
Sitemaps
For bulk changes. An accurate lastmod tells Google which URLs are worth revisiting. This is the correct approach when you have updated hundreds or thousands of pages.
What does not work
Submitting the same URL repeatedly, third-party “indexing services”, and social sharing as an indexing trick. Recrawl time ranges from hours to weeks depending on the site perceived importance and update frequency.
Alien Road recommends: after a large migration, submit the new sitemap with correct lastmod values and then stop touching it. Manually requesting indexing for thousands of URLs is not possible within quota, and the anxiety-driven resubmitting we sometimes inherit from previous agencies achieves nothing except noisy reports.