Why can't I send a text directly from the phone app?

[AC Question]

I get calls from clients who want to register for our training so I want to send a quick text to them with our website address directly from the phone app without having to write down their phone number and go to the text app. My old Galaxy S3 did this easily and now I can't find it on the HTC. Do I need another keyboard app or am I just not finding it on this lollipop OS?