How to add attachment to a Textra Text on Android phone?

[Android Central Question]

I have galaxy note 5 phone and chose Textra as my text messaging app vs the standard messaging app. However, the + button only attaches a picture or something from clipboard. I'm trying to attach a document but there's no " attachment icon like a paperclip. Does anyone know how to send textra text with attachment?

 

[ManiacJoe]

Textra only lets you attach pictures and videos.
This is a common limitation with SMS apps.
Not sure if this limitation has technical reasons or not.