"Divorce according to the Sunnah means divorcing her when she is pure, ( i.e., not menstruating) and without having had intercourse with her (during that cycle)." (Using translation from Ibn Mājah 2020)
أَنْ يُطَلِّقَهَا طَاهِرًا مِنْ غَيْرِ جِمَاعٍ»