1_5057983612117320136 (1).mp4 -

: The "(1)" at the end suggests that a file with the exact same name already existed in your destination folder (likely your "Downloads" or "Telegram Desktop" folder), so your system added a number to prevent overwriting it.

: Found within the "Files" app under On My iPhone > Telegram . 1_5057983612117320136 (1).mp4

: Internal Storage > Android > data > org.telegram.messenger > files > Telegram > Telegram Video . : The "(1)" at the end suggests that