How do I buy B-CHIPS or Crystals in Honkai Impact 3rd?

1) After you pay for the order, I log into your account with provided login and password;

2) In the game, I go to the official store and make a payment for my personal bank card, I receive a purchase receipt (I can send a receipt upon request);

3) I completely log out from the account and you can check that everything has been purchased honestly, after that you confirm the order in the Purchases section, that's it!