It may be useful for you to paste your JSON into a validator first, to see what it says. https://jsonformatter.org/ seems to do the trick.
Just paste your JSON in on the left, and click “Validate”. You can also clean it up to make it look prettier, so you don’t have to think about indenting it or having the same amount of spaces for each line, and so on.
Thanks @codeluggage and @Jici your suggestions were very helpful. I was eventually able to sort it. I had to also check “Queryst.” in the parameters. Thanks again