Remember, magnetic flux is measured in Weber (Wb), and it is a product of magnetic field strength and the area through which the magnetic field lines pass.
Magnetic flux is a measure of the amount of magnetic field passing through a given area. The unit of magnetic flux is the Weber (Wb). One Weber is equal to the magnetic flux that will induce one volt of electromotive force (emf) in a loop of wire when the flux is reduced to zero in one second.
The other units mentioned, such as Ampere (unit of current) and Volt (unit of potential difference), are not used for magnetic flux. Weber is the correct unit used in the International System of Units (SI) for expressing magnetic flux.
Thus, magnetic flux is expressed by the unit Weber.