The easiest way I know of making more psi on a turbo car is to pull the hose from the compressor housing.
I don't recommend this however, this is bad, aka don't do it.
What I do recommend is spending several days/weeks reading this forum and you will find your answers within.
For decent results, you need to replace from the front to the back; intercooler and piping, turbo intake, injectors, valve springs, tune, dump, cat, fuel pump, exhaust.
This will net you gains that most are happy with ie: mid to upper 300rwkw's.
You can go further with e85 ie: over 400rwkw but are asking for a "baxrtuteing".
After that it is turbo swap coupled with engine, trans and driveline building time if you want any hint of reliability.
To answer your question outright about "giving it more psi" you just need a tune.