Text can be either countable or uncountable. If it refers to written or typed word (as in your sentence), it is not countable and does not use an article. (Just like you would not use an article with "writing") If it refers to a book or is short for "text message" then it uses an article.

I think in this sentence text is referring to a block of text and so it uses the word "text" instead of "the text". Another sentence that could use text in this way would be "text flashed across the screen". You can use the phrase "the text" in the following sentence: "read the text in order to understand the question". This is actually really hard to explain and I don't know the exact correct answer...It might also have something to do with the fact that when saying "text" you are referring to a group of words that are isolated from any other words....like digitally...whereas "the text" is a section out of a larger block of words. I hope this helps and doesn't confuse you even further!