what are you using to send the faxes?
In the admin portal you can select the Default cover page, as shown on your screenshots.
If you are sending the fax from the app - you can select what cover page to use:
Pic1 - default cover page is Birthday
Pic2 - can change it to None
 

what are you using to send the faxes?
In the admin portal you can select the Default cover page, as shown on your screenshots.
If you are sending the fax from the app - you can select what cover page to use:
Pic1 - default cover page is Birthday
Pic2 - can change it to None
 

 

 

we don’t use ringcentral interface to send faxes, we’re sending it via ringcentral-api

I hope @PhongVu can help you. He posts frequently on the developer platform side.
As is visible from my screenshot Blank and None are 2 different options, but for some reason you can’t select None as your default cover page in the admin portal.  

To send a Fax w/o the cover page using the Fax API, set the coverIndex to zero.

var body = {
      to: [{phoneNumber: RECIPIENT_NUMBER}],
      faxResolution: 'High',
      coverIndex: 0
    }
var FormData = require('form-data');
formData = new FormData();
formData.append('json', new Buffer.from(JSON.stringify(body)), {
    contentType: 'application/json'
});
...

Next time, please post questions relating to RingCentral platform API to the “Developer Platform, APIs & Integrations” category.

Thank you!
it was helpful