USDC depositing can be done in 2 ways which are:
Option 1: Deposit USDC using Copy/Paste USDC wallet address
1.1) Log in to Bitkub.com
1.2) Click My Wallet
1.3) Select USDC Deposit
1.4) Copy Address into the sender page.
Option 2: Deposit USDC using the QR code (Only for the sender wallets that support the QR Code scan function)
2.1) Log in to Bitkub.com
2.2) Click My Wallet
2.3) Select USDC Deposit
2.4) Scan QR Code to specify USDC wallet address
2.5) Your deposit transaction will be shown in the box at the bottom part of the website called "TRANSACTIONS".
2.6) USDC transactions will be considered complete once it has 25 confirmations on the blockchain.
You can read more information about block confirmation here.