Quick answer — IDOLiSH7 performed 1 anime theme, including "WiSH VOYAGE" from IDOLiSH7.
IDOLiSH7 performed the anime theme songs "WiSH VOYAGE" (IDOLiSH7).
IDOLiSH7's first listed anime theme is "WiSH VOYAGE", the opening of IDOLiSH7.