GLS periodogram of the TOI-815 spectroscopic and photometric time series. More specifically: (1) RV ESPRESSO measurements, (2) RV residuals, after the subtraction of TOI-815c signal, (2) RV residuals, after the subtraction of TOI-815b and c signals, (3)-(5) FWHM, bisector, and Ca II H & K line activity indicator (logR′_HK), (7) TESS Sector 63 photometric data, and (8)-(10) WASP photometric data (2008, 2012, and 2023). The two black vertical lines correspond to the minimum and maximum rotation periods (P_rot,mim ~ 14.2 days and P_rot,max ~ 16.5 days). The purple and orange vertical lines correspond to the orbital periods of planets b (P_b ~ 11.2 days) and c (P_c ~ 35 days), respectively. The gray horizontal lines indicating the 1% FAP.