You can use the InsertField Single Message Transform (SMT) to add the message timestamp into each message that Kafka Connect sends to a sink.
To use the Single Message Transform specify the name of the field (timestamp.field ) that you want to add to hold the message timestamp:
" transforms " : " insertTS " ,
" transforms.insertTS.type " : " org.apache.kafka.connect.transforms.InsertField$Value " ,
" transforms.insertTS.timestamp.field " : " messageTS "
Read more: 🎄 Twelve Days of SMT 🎄 - Day 1: InsertField (timestamp)