_Send_email not working when action trigger by Sales rep

Hi,

We have a requirement to send notification to submitter and quote owner on approve action. For example, on request approval action if 1 user approve quote then submitter and owner should get the notification on email, we are using _Send_email rest API to send email. the issue is, when admin trigger the approver action then owner and submitter received the notification but when sales user approves the quote no one receive the notification.