Guitar hero PS3 controller connectivity

I need help finding dongles for my guitars!! I became obsessed with guitar hero at the start of this year when I came across old photos and videos of my friends playing when we were little, I bought a PlayStation, so many games and two guitar hero controllers not knowing anything at all and they didn’t come with dongles :( I was told that for the dongle to connect properly, that the serial numbers on the back of the guitar and dongle need to match but I was looking for more guidance as the one cohesive thing that everyone has to say about the PS3 version of guitar hero is that it’s so overly complicated when it comes to connectivity! Thank you so much in advance :)