What is the SI unit of magnetic flux?

A rectangular solar-instrument panel is $1.5$ $\text{m}$ high and spans $x=0$ to $x=2.0$ $\text{m}$. The magnetic field through it is $B\left(x\right)=4x$ $\text{T}$, normal to the panel. Find the magnetic flux.

A vertical rectangular surface has height $H$ and spans $x=0$ to $x=a$. A magnetic field $B\left(x\right)$ points horizontally through the surface, making a constant angle $\theta$ with the outward area vector. Which expression correctly represents the flux?