وَيَسْتَقْبِلُ بِهِمَا الْقِبْلَةَ
Translation: He faces the qiblah for both adhan and iqamah.
Facing the qiblah is an established manner of both calls.
Failure to face the qiblah is treated as a matter of the manner and etiquette of adhan rather than a nullification of the prayer time announcement itself.