You need the app Messages by Google (details in the following link https://messages.google.com/). Note that this app does not work on an iPhone (or on a tablet with iOS).
Click the Browse Contacts button. It opens a table with your contacts on the browser area. If you have more than one page of contacts, the button More will appear on the table. You can move between the pages, by clicking this button (which is eye-gaze enabled). Once you are ready to select a specific contact, click the Select button and select a contact using eye-gaze. Then click Exit to go back to SMS home page, to send and review messages to/from this contact.
Use the Next Contact and Previous Contact buttons to navigate between your contacts. Once a contact is highlighted you can use the Chat Up and Chat Down buttons, to go over this contact messages and read them.
Use the Next Contact and Previous Contact buttons (or Browse Contacts) to navigate to the contact that you are interested in. Once the contact is highlighted, click Chat View, and use the Message buttons (up and down) and Scroll Chat buttons (up and down) to get to the message you want to select.
Click the Search Gif and type in the search phrase. Then use the arrows to select the gif you want to send. Once it is highlighted, click Select Gif to send it.
This button allows you to send a message to a group of contacts. After clicking it, you will be asked to add contacts to the group. Once you are done, you can click Start Chat and send the message to the group.
You need to click send, only when the file / picture that you want to send is selected. If you click Send when a directory is selected, nothing will be sent, and the dialogue box for selecting a file / picture will be closed.