Convert to URL to ASCII

i'm trying to convert this url:

http://example.com/Gênesis/141588.mp4?AccessKey=3334ee81-a1ee-4f91-8cb5e4edfe1d-9a66-4144&download

to this one:

http://example.com/G%C3%83%C2%AAnesis/161680.mp4?AccessKey=3334ee81-a1ee-4f91-8cb5e4edfe1d-9a66-4144&download

I used this command to detect the enconding of the second url and it says that it is ASCII: echo mb_detect_encoding($str);

and then I tried to convert it to ASCII using this mb_convert_encoding($str, "ASCII");

but the url stays like this: http://example.com/G?nesis/141588.mp4?AccessKey=3334ee81-a1ee-4f91-8cb5e4edfe1d-9a66-4144&download

help.

source https://stackoverflow.com/questions/67909615/convert-to-url-to-ascii