Finally, I manage to fix the issue.
In documentation, its not mentioned that sitemap.xml need to be there as pre requisite before running the crawler.
I followed following steps to resolve the issue:
1- Configure the sitemap plugins:
https://docusaurus.io/docs/api/plugins/@docusaurus/plugin-sitemap
2- run
npm run build
3- Now server my site in local on port 80.
npm run serve
4- Run the typesense server
5 - Run the scrapper
Thanls
@Jason Bosco for your proactive support.