Email from Workflow only doesn't work!

Server = Ubuntu 22.04.2 LTS
XAMPP = /opt/lampp/
SuiteCRM Version = 7.13.3
SuiteCRM = /opt/lampp/htdocs/suitecrm
PHP Version = 8.0.28
SMTP Server = Gmail Port 465 SSL
OAuth Client created with ID, Secret, Allowed Grant Type: Client Credentials

I am currently facing an issue with the SuiteCRM API to create access token, specifically regarding access to the https://mydomain.com/api/access_token endpoint. I have followed the SuiteCRM API documentation and various online resources to configure the API properly, but I keep encountering the following error:

{
“error”: “access_denied”,
“error_description”: “The resource owner or authorization server denied the request.”,
“hint”: “The JWT string must have two dots”,
“message”: “The resource owner or authorization server denied the request.”
}

I have performed the following steps to troubleshoot the issue:

I have confirmed that the server time is accurate and that the mod_rewrite module is properly configured in the virtual host file. Additionally, I have followed the SuiteCRM API setup guide to ensure all recommended steps are completed.

Regard,
Naushad Khan