For the Netlify plugin, crawlers cannot be created manually for the Netlify site.
Instead, the crawler is created after you trigger a deploy of your site in Netlify, and subsequent crawls are triggered by any deploys after this: https://www.algolia.com/doc/tools/crawler/netlify-plugin/quick-start/#indexing
If you're creating a new Netlify site it will need to be created in Netlify first, then added in the Algolia Crawler Dashboard under the Netlify tab. A deploy would then need to be triggered for this new Netlify site:https://www.algolia.com/doc/tools/crawler/netlify-plugin/quick-start/#link-your-site-to-algolia
The free Netlify plan, doesn't include technical web support from the Support team.