Gauss law of magnetism describes that divergence of magnetic field will be zero while divergence of electric field is not zero which shows the non-existence of magnetic monopole. As per Gauss law of magnetism

Magnetic monopole is a hypothetical magnet which has one of the pole only i.e. either north or south. If it exists, then the Gauss law of magnetism disobeys and then as per the gauss law electric field the divergence of magnetic field is proportional to the magnetic charge density. But this is just an idea till now no magnetic monopole has found If monopole exists, then the right side will be equal to the monopole which is multiplied by μ_₀.