x-api-key: ********************curl --location '/campaigns/statistics?from=undefined&to=undefined' \
--header 'x-workspace;' \
--header 'x-api-key: <api-key>'{
"sent": 0,
"delivered": 0,
"opened": 0,
"clicked": 0,
"replied": 0,
"bounced": 0,
"unsubscribed": 0
}