Left panel: raw $p_{\rm T,ee}$-differential yield ($S$) in peripheral (70--90\%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV for $0.7 \leq m_{\rm ee} < 1.1$ GeV/$c^2$ overlaid with the opposite charge-sign distribution ($OS$) and the same charge-sign spectrum multiplied by the acceptance correction factor $R_{\rm acc}$ ($B$). Right panel: signal over background as a function of $p_{\rm T,ee}$ in peripheral (70--90\%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV for $0.7 \leq m_{\rm ee} < 1.1$ GeV/$c^2$.