Hi,
Thank you for reaching out to us.
To configure your gateway provider with the plugin check our FAQ.
For Gatewayapi.com API URL-
https://gatewayapi.com/rest/mtsms?token=Go-Create-an-API-token&message=##meessage##&recipients.0.msisdn=##phone##
Kindly replace the highlighted values with the respective details from your gateway dashboard.
We would be happy to take a look and help you resolve the issue.
Would it be possible for you to drop us a query at otpsupport@xecurify.com.
Waiting for your response.