Hi, I have tried different power connectors to use with the pico psu but non of them are compatible. Which size or type is adapted to the pico psu ?

I went with this one https://a.co/d/iTSCZUC, however assuming you got the one from Turing, the key aspects are 12V with a 5.5x2.5mm barrel plug. Turing recommends that the supply be capable of 10-12 amps (120-144 watt) however if you are not planning on adding many disks or other devices you could go smaller. If you already have a power supply but it has the wrong tip, you can get just the barrel pugs and hack it together, however you need to make sure you get the polarity right.

I see laptop charger there. Make sure you get a 12V power supply. It must be 12V