Two men came to the Prophet ﷺ with the intention of a journey. The Prophet ﷺ said, "When (both of) you set out, pronounce Adhan and then Iqama and the oldest of you should lead the prayer." (Using translation from Bukhārī 630)
أَتَى رَجُلَانِ النَّبِيَّ ﷺ يُرِيدَانِ سَفَرًا فَقَالَ النَّبِيُّ ﷺ «إِذَا أَنْتُمَا خَرَجْتُمَا فَأَذِّنَا ثُمَّ أَقِيمَا وَلْيَؤُمَّكُمَا أَكْبَرُكُمَا»