I am a new comer to using API for OpenProject. 

I am a little lost and am wanting for more examples and tips for how to use Filter APIs to achieve what I want to do.

For example, here in the documentation says "simply copy the URL from your browser to get the resulting filter values"

However, I got this confusing "query_props" values instaed of "filter" values I was expecting.

Not only the documentation has no mention of "query_props", the resulting URL did not work for my instance of OpenProject. 

So I went to my instance of OpenProject, and selected the filters on my page.

The resulting query_props value was

query_props=%7B%22c%22%3A%5B%22id%22%2C%22subject%22%2C%22type%22%2C%22status%22%2C%22priority%22%2C%22assignee%22%2C%22startDate%22%2C%22dueDate%22%5D%2C%22hi%22%3Atrue%2C%22g%22%3A%22%22%2C%22is%22%3Atrue%2C%22tv%22%3Afalse%2C%22hla%22%3A%5B%22status%22%2C%22priority%22%2C%22dueDate%22%5D%2C%22t%22%3A%22id%3Aasc%22%2C%22f%22%3A%5B%7B%22n%22%3A%22status%22%2C%22o%22%3A%22c%22%2C%22v%22%3A%5B%5D%7D%2C%7B%22n%22%3A%22startDate%22%2C%22o%22%3A%22%3Et-%22%2C%22v%22%3A%5B%2230%22%5D%7D%5D%2C%22ts%22%3A%22PT0S%22%2C%22pp%22%3A50%2C%22pa%22%3A1%7D

However, this did not give any results when I used this for my API query.

I wish there were more examples, tips and guides for using Filters for new comers like me.