Transaction ID/hash is mostly used to check the status of the transaction on the Blockchain. However, you may also see some other important transaction details like the wallet addresses from and to which the assets are sent, the time of the transaction, the number of confirmations received etc.
To find the transaction ID/hash on CEX.IO website:
Log in to your account;
Go to the Finance page and choose the Transactions tab;
Find the transaction in question and check the Comment section next to the transaction details.
To find the transaction ID/hash in CEX.IO app:
Log in to your account;
Tap the Wallet menu at the bottom of the screen;
Choose the cryptocurrency you want to find the transaction details for;
Tap the Payments button;
Tap the deposit/withdrawal in question.
