Search results are delayed

What do you do when the website shows the search result with a delay?

I'm looking into making a source for Storytel but the html I get back from the script is not complete, the search results are missing. When going to the search page directly I can see that the results load after the page has been loaded. Can I delay the scripts until the page is fully loaded?

The search page

Storytel has Json, you can use mine as a base: Mp3tag/data/sources/Storytel JSON.src at master · romanoh/Mp3tag · GitHub , don't know if its working.