About your "aviary" - as soon as someone decides to remove you from where ever you are "camping", it will get destroyed since it is hopefully too big to carry it away.
Not a proper solution.
I live in a community, which is in this place for more than 10 years (since 2013). The authorities know that this community is here from the beginning. I have good friends. Even they recommend the aviary.
What have you been feeding the last 2 birds?
Pigeon, mouse and chicken meat.
You bought some medicine for the bird on the internet.
Because the bird had feather lice.
Check the condition of the bird you kept in Hungary starting on September 2022, you made enough posts. Read your own words, especially when your birds condition changed massively.
Ask yourself what and why things went wrong.
I already wrote this down in one of my blog posts. The bird had many feather lice. She went into a center, where veterinarians successfully cured her from this. Initially after that, her condition seemed promising, but suddenly she died because of heart failure. The size of the heart of the bird was different from normal. Even the veterinarian necropsy could not find out the reason behind this.
You can see the depression in the eyes.
Hopeless, enjoy your life. :)
You may understand next time if you can't stop yourself from buying another bird.