curl --request POST \
  --url https://api.virtuoussoftware.com/api/VolunteerOpportunity/{volunteerOpportunityId}/Volunteers/{volunteerId}/Attendance \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "timeZone": "<string>",
  "hours": "<double>",
  "startDateTimeUtc": "<dateTime>",
  "endDateTimeUtc": "<dateTime>"
}
'

{
  "id": "<integer>",
  "volunteerAttendanceUrl": "<string>",
  "volunteerId": "<integer>",
  "volunteerUrl": "<string>",
  "volunteerOpportunityId": "<integer>",
  "volunteerOpportunityUrl": "<string>",
  "hours": "<double>",
  "startDateTimeUtc": "<dateTime>",
  "startDateTime": "<dateTime>",
  "endDateTimeUtc": "<dateTime>",
  "endDateTime": "<dateTime>",
  "timeZone": "<string>",
  "createDateTimeUtc": "<dateTime>",
  "createdByUser": "<string>",
  "modifiedDateTimeUtc": "<dateTime>",
  "modifiedByUser": "<string>"
}