Magnetic flux is given as ϕ=BScosθ ...(i)
Here is B magnetic field and S is area.
Magnetic force F on a charge q moving with velocity v is given as F=qvBsinβ
So, B=qvsinβF .............(ii)
By equations (i) and (ii) ϕ=qvsinβF×Scosθ
Trigonometric functions are dimensionless
so ϕ=qvFS=AT×LT−1MLT−2×L2=ML2T−2A−1