The study aims to precisely measure the \(e^+e^-\rightarrow \pi ^+\pi ^-\) and \(e^+e^-\rightarrow \pi ^+\pi ^-\pi ^0\) cross sections from collision data at Belle II. These measurements are intended to improve the theoretical predictions of the muon’s anomalous magnetic moment, currently showing a 5.1-sigma deviation from Standard Model expectations—a hint of possible new physics. Using high-luminosity data at Belle II, we employ the initial-state radiation technique to achieve continuous cross-section measurements across energy ranges starting from the dipion threshold, reducing systematic uncertainties. The three-pion cross section has recently been measured, and we are now targeting 0.5% precision in the two-pion cross section. These results are essential for calculating the hadronic vacuum polarization contribution, the largest source of uncertainty in muon anomaly predictions due to the complexities of QCD.