I mean, as I understand it, the U.K. wanted to relieve their trading offset - They purchased too much tea, and the Chinese purchased too little British goods. The Chinese basically said they had no need for British manufactured goods.
Did the British seek to sell rifles, ships, and cannons to the Chinese? AFAIK they had relatively few firearms in their arsenal. Why, or why not?
More can of course be said, and I must admit I am not at all familiar with the British side of the equation, but on the Qing side it seems that there was generally not much interest in purchasing large amounts of weaponry wholesale before the crisis of the 1850s-60s. Rather, they focussed on obtaining a few examples, and the knowledge and expertise required to actively produce the weapons themselves. I briefly lay this out in a sub-chain of this answer.