I have an ancient coin that says "Tianyuan Bao Tong". I don't know which dynasty it belongs to.

Kaiyuan Bao Tong was first cast at 62 1 in the fourth year of Wude, Tanggu, with a weight of one or two per kloc-0/0. Ou Yangxun coined words and combined them into a book, using [stars]. ] [Moon] and other back decorations-there was also a Kaiyuan Rebel in the Qing Dynasty, and one would be cast in heaven and earth-there was [Wu] behind it.