For me ignoring worked, but that could have just been because my second hand parrots were screaming because they were terrified of human company and not because they wanted attention.
I got a book, some food and sat with my back to the cage until they stopped screaming (Over 5 hours without a toliet break
), helped that I had earplugs though and that I did it the second day I had them.
Maybe your parrot just likes screaming, are there any fun foraging toys you could get?