Fret buzz on brand new Martin - Fix or return?

Hi there - I purchased a brand new Martin 000C Jr E and after about 30/40 minutes of playing the D string started to buzz (very loudly).

I sent an email to the online store I bought it from and they recommended to fix it by adjusting the truss rod. If that doesn't fix it they said that I can return it.

I don't own the specific type of Allen key needed to perform this. I also am not sure if it is a wise decision to try fix it. I can also return the guitar to their returns department where they will fix it.

Any advice on whether to perform the fix myself, return it, or other option would be greatly appreciated :)