U is fixed, and to increase the current, you can only reduce R. Oh, where R is the resistance and the sum of the internal resistances of the load and the power supply, that is,

I=U/(R 1+R2), assuming that R 1 is the load resistance, R2 is the internal resistance of the power supply, and your R 1 is fixed, then you can only solve R2, that is, reduce it. Friend, change a higher power supply, or use two power supplies in parallel.