Almost all exchanges require a Memo ID (XLM) or a Destination Tag (XRP) for transactions to successfully be transferred to your wallet, if you did not include this on the withdrawal, you will have to contact your exchange to see if they can recover your coins. They will need the Transaction ID, this is sometimes called "Payment ID", "Transaction Hash", "TX: ID" or something similar, you can find it in your Celsius app withdrawal history.
Example of an XLM transaction without a Memo ID:
Example of an XLM transaction with a Memo ID:
Example of an XRP transaction without a Destination Tag:
Example of an XRP transaction with a DEstination Tag: