The two sentences have a slightly different meaning but both of them express equally that you still work at the company, but for different reasons. In the first it’s because of the words ‘since 2013’ and in the second it’s because of the words ‘I’ve been working’
The difference in meaning is that the first sentence talks about how your present situation is affected by past events. The second talks about your activity in the past. Examples:
Are you an experienced employee now?
Yes, I’ve worked here since 2013.
What have you been doing in the recent past?
I’ve been working here.
Of course you can answer both questions with either of your sentences, but only in the examples above are the answers consistent with the focus of the question.