Twilio Sms Mobile Login module depends upon the core module named Core and on Twilio SDK, so you need to install it.
Steps to install Core Module:
1: Using the composer:
For installing the core module you need to run following commands.
composer require wbcomdesigns/module-core:dev-master
2: Through FTP/SFTP:
You can download this core module from the following links
https://github.com/wbcomdesigns/wbcom-core-module-magento.git
Now connect your FTP/SFTP and upload the modules related folder and files.
Your directory path will be Magento_Root/app/code/Wbcom/Core
Steps to install Twilio SDK:
(b) This module also depends upon Twilio SDK so you need to install it.
Using Composer: Run the following commands
composer require twilio/sdk
Important Note:
(a) The core module is related to Wbcom packages, and for the proper functioning of any packages related to Wbcom, it is strictly required to install this module.