Turn the knob to 200m near the 9-O'clock position.
that scale will read from 1 to 200mV with the highest resolution. If you are measuring 200mV to 2 volt angle, the change to the 2V range jsut next to the 200m range.
I am assuming you mean milliVolts DC. Your meter cannot measure low voltage AC.
Also understand that the Scale is 0-200mv and that a reading on that scale of 0.001 is actually 1uV. Would have helped to be able to see the resolution of the display, ie how many digits it is. Also read the specifications of the meter in your manual for it.
Resolution at the 200mV scale is 0.1mV, based on the vendor's web site for that model. It is a 4 digit meter. Accuracy is +/- (0.5%+3), meaning one can be off by at least 3 digits at the bottom value (ie 0.3mV accuracy only, on 200mV scale) https://mastech-group.com/eu/en/MAS830B