Supported TLS protocols are defined [here](https://github.com/SourceLabOrg/kafka-connect-client/blob/e5d5888952efd0b4579d9295e5caa260495f7fc7/src/main/java/org/sourcelab/kafka/connect/apiclient/rest/HttpsContextBuilder.java#L55) TLSv1.3 is in wide use today and is missing.