u/Far_Outlandishness_8

I'm making my own texture pack and I've changed almost all the buttons for trading with villagers, but I can't find the path to the button for selecting trades (the gray one). It's not in the container sprites, and in the GUI texture folder, it's only the background. What should I do? Where's the path?

https://preview.redd.it/51bca41f1a0h1.png?width=843&format=png&auto=webp&s=63dac254375b8dae9f2c706adcd3d1b111e32ebc