Scarpe sensor table

Hi
The user guide for how to create Scarpe sensor is not very detail.

I use now scarpe sensors for simple html webpage, and that’s works fine.
But now I have plan to scrape a hmtl webpage there include a table.
How do HA scarpe search in table?
Is there any tools for debugging scrape sensors for HA?

Any other realted issue to HMTL and URL. How do I create a “resource” URL from a variable?
The URL is fix in the configuration file, and can not be change?