Can I increase gas pressure to a stove?
The stove will have a gas regulator on it, so assuming that it is performing as-expected, you cannot increase the pressure in order to generate more heat.  The stove is designed to accept a range of pressures from the supply line to begin with and increasing the pressure beyond what the regulator is designed for would be dangerous.

If the flame is mostly blue then this is a good sign that the pressure and oxygen mix is correct and it is probably performing to spec.  If the flame is mostly orange/yellow or appears "lazy", then this is a good sign that it is not burning properly either because the pressure is too low (due to supply, regulator or a blockage) or there is not enough oxygen being mixed in (clogged).

If the regulator is bad then this can be replaced.  If the supply to the regulator is too low then you likely need a bigger supply line. Both of these are outside the realm of most DIY repairs, so best bet is to call a service technician.