# Action of 1-form symmetry in Maxwell theory

I am reading Lectures on Gauge Theory by David Tong 1. In 3.6.2 first example that the author talk about pure $$U(1)$$ gauge theory in 4D. In this example, he talk about two 1-form symmetries: electric $$U(1)_e$$, with 2-form current $$j_e \propto *F$$, and magnetic $$U(1)_m$$, with 2-form current $$j_m \propto F=dA$$. It is mentioned that the action of the electric 1-form symmetry on the gauge field $$A$$ is a shift by a flat connection $$\lambda$$, i.e., $$d\lambda=0$$.

How I can calculate it? Is it possible derive current from Lagrangian using knowledge about action on fields?