continuous fraction for 30/pi^2

I read that $ 30/pi^2 $ can be represented as a continued fraction of the form

$$ 3 + frac{1}{25 + frac{16}{69 + frac{…}{…}}}
$$

over here: http://www.ramanujanmachine.com/wp-content/uploads/2020/06/pi_square.pdf

where can I find the proof? I haven’t come across such fractions before. When I looked it up, I could only find proofs for $pi$ or $1/pi$ but not anything to do with $1/pi^2$.