Questions About Choosing a Shunt Resistor

I’m trying to do a power analysis on my target, which runs on 3.3 volts. Without the resistor, the average current while running is roughly 140mA.

I used a 10Ohm resistor as a shunt resistor with a 5V power source. The voltage difference between VCC PIN and GND was measured using a shunt resistor linked between 5V and the target VCC pin. (The decoupling capacitors have been removed.) On the other hand, the oscilloscope lacked a proper power consumption line.

Is there a problem with my setup? Is there any guidance on how to choose a shunt resistor?