Update an email template
JWT Bearer token authentication using the Authorization header
welcome_email, password_reset, email_verification, invitation Template updated successfully
"welcome_email"
"Welcome to {{app_name}}!"
"<h1>Welcome {{user.name}}!</h1><p>Thank you for joining us.</p>"
"Welcome {{user.name}}! Thank you for joining us."
["user.name", "user.email", "app_name"]