Instant Timestamp not showing in mysql

I am using Instant in java to store timestamp in mysql database:

However when getting the data from database it shows null.

Here is my code snippet:

@Entity
@Table(name="trade_data")
public class TradeData {

@Column(name = "creationTimeStamp",insertable=false)
private Instant CreationTimeStamp;


@Column(name = "VersionTimeStamp", insertable=false)
private Instant VersionTimeStamp;

}

    public ResponseEntity<?> addTrade(TradeData trade) {

    boolean validDate = false, validTrn = false, validBuyerSeller = false, validPartyCparty = false;
    
    trade.setVersion(1);
    trade.setTradeRefNum(trade.getPartyCode(), trade.getTradeId());
    trade.setS_no(0L);
    trade.setTradeDate(new java.sql.Date(System.currentTimeMillis()));
    trade.setCreationTimeStamp(Instant.now().truncatedTo(ChronoUnit.MICROS));
    trade.setVersionTimeStamp(Instant.now().truncatedTo(ChronoUnit.MICROS));

}