Here’s a breakdown of the string:
Avengers.Endgame.2019.2160p.UHD.BluRay.X265.10b... Avengers.Endgame.2019.2160p.UHD.BluRay.X265.10b...
A legal 4K Blu-ray rip you make yourself (for personal backup where permitted) wouldn’t include scene release group names or be tagged with pirated release conventions. Here’s a breakdown of the string: Avengers