I think the difference between testing intelligence and knowledge is that the former one is a bit vague and very difficult to measure directly. The latter one is a straightforward test, we usually take such knowledge tests often at the school level. I think knowledge tests are appropriate when someone is learning/taking that knowledge, can be compulsory. In comparison, the intelligence test is appropriate only by consent, if people want to take it, should be voluntary.

So I googled "IQ test" and used https://www.123test.com/iq-test/#culture-fair-intelligence-test this one to test my IQ. The website says my IQ is "a range of 121 up to 137." I think this free sample IQ test has many weaknesses and a few strong points. First, it has only 8 questions, which gives a wide range of random errors. Second, the questions are quite repetetive and if you get how they are build it gets easier. Third, it does not count the time spend on solving a puzzle. The strengths are: it asks for some background information (age, education) which if added to the formula should adjust the IQ results and it uses abstract images.