  The purpose of this paper is to examine the epicyclic motion of charged
particles in the vicinity of a magnetically charged stringy black hole subject
to an electromagnetic field. This investigation is motivated by the established
fact that magnetic fields have a significant impact on the motion of charged
particles in the vicinity of a black hole. It has been observed that the
magnetic coupling parameter has a comparable impact on the motion of magnetic
monopole charge, leading to an increase/decrease in the radius of the innermost
stable circular orbit (ISCO) that plays a crucial role in setting the accretion
disk's the inner edge. Further, we analyze the characteristics of the epicyclic
motion and determine the generic form for the epicyclic frequencies. Our
results demonstrate that the existence of the magnetic coupling parameter can
account for the observed resonance of high frequency QPOs from selected three
specific microquasars. We have applied the Monte Carlo simulations with the
observed frequencies for three selected microquasars to constrain the
parameters of the magnetically charged stringy black holes as well as coupling
parameters that describe the interaction between the particle and the black
hole. Finally, we study in detail the radiation properties of the accretion
disk in the close vicinity of black hole. We show that the magnetic coupling
parameter can have significant influence on the radiation flux of the accretion
disk.
