You must from your own console. Downloading BIOS files from the internet is copyright infringement in most countries.
The ps1-rom.bin file is not publicly available due to copyright and intellectual property concerns. However, it can be obtained through various means, such as: ps1-rom.bin bios
He tried an HTTP mirror. 404 Not Found. He tried a torrent. No seeds. You must from your own console
This guide explores what the PS1-ROM.bin file is, why it is necessary for emulation, and how to use it responsibly. What is the PS1-ROM.bin BIOS? why it is necessary for emulation