curl --location --request PUT '/smartflows//triggers/mail-open/' \
--header 'Authorization: Bearer JWT' \
--header 'Content-Type: application/json' \
--data '{
"name": "Custom activity name",
"duration": {
"value": 24,
"unit": "minute"
},
"trigger": "open",
"campaignId": "4a06896c-81b3-44f4-b493-2057bef951a2"
}'{
"error": "Reason of failure"
}