Yahoo changed their API a while ago. So v6 does not work anymore. See this post how data can be retrieved currently. No guarantee on how long this will work. You may have to use their website to see which identification they use for the data you are looking for (might not be ISIN).
What works for my quotes on yahoo is the same as yours except:
Identify by: Symbol
URL: https://query1.finance.yahoo.com/v8/finance/chart/%1
Don’t hesitate to write back if you have questions. Happy Mardi Gras! A