You can change your account password via App or Website.
Changing account password via App
To do so, go to the Me tab via Shopee App > Select ⚙ Setting Icon > Select My Profile > Select Change Password > Enter Current Password as verification and select CONTINUE > Enter New Password > Select RESET.
Changing account password via Website
To do so, go to shopee website homepage > Select your Username on the top right corner > Select My Account > Select Change Password > Enter your current and new account passwords > Select Confirm