In the training mode, you have the opportunity to buy it at the grocery store.
Have the opportunity to get treasures through excavation (there are several kinds of treasures)
You can get a copybook with Li Wei's answers in Luoyang Town.
If the appraisal skill reaches 70 in the towns of Hangzhou, you can buy an authentic umbrella from Tang Bohu.
In the Great Map Raiders, Leshan Giant Buddha saved Tang Bohu and got its original fan.
There are basically several ways.