put https://my.surveypal.com/api/rest/survey//answer/email/invite
Send an email invitation to the survey.
Will send an email invitation to the survey. Email subject and message are freely editable. If you don't send message then invitation message will be the one what you have saved to the survey.
curl -i -X PUT \
-H "Authorization: Basic YOUR-USERNAME-AND-TOKEN-BASE64-ENCODED" \
-H "Accept:application/json" \
'https://my.surveypal.com/api/rest/survey/:id/answer/email/invite?email=:email&unique=:unique&anonymous=:anonymous&meta=:meta&localeId=:localeId&author=:author&replyTo=:replyTo&subject=:subject&message=:message&sendAt=:sendAt'