AUTO TRANSACTIONS doesnt work.

The AUTO TRANSACTIONS skill isn't working; it doesn't sell the cans once a minute.

I'd also like to request that, instead of fixing it, it be modified to: Automatically sell when you reach the maximum number of cans. In other words, instead of getting a message that your inventory is full, it should automatically sell everything—that makes the most sense, and it's also an endgame feature.

Thanks for the idea! I’ll rework the upgrade so that selling will also trigger automatically when your backpack is full.

To make Auto Sell work, you need to purchase at least one level of Online Transactions + Auto Transactions. 
After that, press the "Z" key to activate Auto Sell, it works the same way as Auto Attack. When active, an icon will appear in the upper right corner of the screen.

 Just updated the game, now Auto Sell will trigger automatically ( if it turned on ) when backpack is full.