Coolant / Antifreeze ? Help Please UK/Europe

Tayzer

Hey, So first off, super sorry as i'm sure this has been asked before and it's a stupid rookie question I did a forum search and couldn't find anything.

I need to top up/change my coolant/antifreeze but I cannot for the life of me find out what to use. I've asked garages, car specialists shops and everyone says check the manual but it says to use 999MP-L25500P only. Now I cannot find anyone with stock and not sure of what else if anything I can use. I'll find loads of years old threads from various places and they all say a multitude of different things. Literally people saying I use red, I use green, I use blue, I use silicone free, I use silicone 50/50 and i'm just worried

UK / European Car - 60 Plate (2011) - Any help would be appreciated. Please feel free to call me an idiot too but only if you can help