hi! i plan to bring one set of musical instrumen (angklung)and some key chains (around 20) as a gift

i bring them for an cultural exchange program in fujian. if i leave them in china as a gift do i need to declare them and pay tax? if yes how much money do i need to pay? and if i bring them back to indonesia do i still have to declare them and pay tax too?

please help me, thank you :)