Unable to send SMS with certain users

Good morning, I am developing an application with ringcentral, it is already finished but in the tests we discovered that when we log in with certain users and send a SMS fails.

We send the message with the API:
/restapi/v1.0/account/accountId/extension/extensionId/sms

And the error shown in console is as follows: Phone Number Doesn't belong to extension

The way we send the message is like this:

const sendSMS = await this.platform.post(
"/restapi/v1.0/account/~/extension/~/sms",
{
"from": {
"phoneNumber": that.senderPhone
},
"to": [
{
"phoneNumber": that.Mobile
}
],
"text": that.smsText});

Where that.senderPhone is the phone of the user that is logged and to is the remitent