After they set out from Kadesh, the entire Israelite community came to Mount Hor.
References for Numbers 20:22
The Lord said to Moses and Aaron at Mount Hor on the border of the land of Edom,
"Aaron will be gathered to his people; he will not enter the land I have given the Israelites, because you both rebelled against My command at the waters of Meribah.
Take Aaron and his son Eleazar and bring them up Mount Hor.
Remove Aaron's garments and put them on his son Eleazar. Aaron will be gathered [to his people] and die there."
So Moses did as the Lord commanded, and they climbed Mount Hor in the sight of the whole community.
After Moses removed Aaron's garments and put them on his son Eleazar, Aaron died there on top of the mountain. Then Moses and Eleazar came down from the mountain.
When the whole community saw that Aaron had passed away, the entire house of Israel mourned for him 30 days.