On a PS2 you can use FreeMCBoot memory card to run homebrew

Buy one with FMCB preloaded from AliExpress, and take it from there

https://consolemods.org/wiki/PS2:FMCB

And also check out for example MX4SIO as well

You can buy one of those from AliExpress as well, but only certain versions of FMCB are compatible with MX4SIO out of the box