How to send an invoice by email with API ?

Hello,

I'm trying to send an invoice by email with the API but I always get this error :

{

"code": 57,

"message": "You are not authorized to perform this operation"

}

This is my request :

https://www.zohoapis.com/books/v3/invoices/{invoiceId}/email?organization_id={organizationId}

I use a header with a Oauth Token generated with the scope ZohoBooks.fullaccess.all and the body contains the contact_id of the contact used to create the invoice.

What am I doing wrong ? What is the missing authorization ?

Thank you for you help,

Brenda