Modify a Data-group with iControl Rest

I'm trying to add a record to an existing data group. I can create the datagroup with records, but I can't figure out the syntax to add a new record to the datagroup w/o overwriting the entire DG.

Here is the command that I've been using to create the DG, how do I modify it to modify/add instead of overwrite?

curl -k -u admin:f5rules -H "Content-Type: application/json" -X PUT -d '{"records":[{"name":"123","data":"435" }]}' https://1.0.1.6/mgmt/tm/ltm/data-group/internal/~Common~TEST_iRule | /var/tmp/jq .

Thanks!