The sandals of the Messenger of Allah ﷺ had two straps.
أخبرنا محمد بن معمر قال حدثنا حبان قال حدثنا همام قال حدثنا قتادة قال
أن نعل رسول الله ﷺ كان لها قبالان
No references are available.
Bukhari (Clothing, chapter on two straps on a sandal, and on those who considered one wide strap sufficient, no. 5857) reported it from the hadith of Hammam bin Yahya with the same chain.