Indeed, it was added in March 7th, 2021 (Patch 11.6):
HOTKEY BLING When the shop is open, you can quickly select items in your inventory by pressing their number keys. Unleash your inner speed shopper!
Can you make right click work with buttons in the new shop like it did in the old shop? The old shop was much faster to use because we didn't need to switch mouse buttons. We could single right click items to purchase and right click on any buttons (undo, purchase, sell, close) and even right click to navigate.
That’s actually a pretty good idea. I’ll chat with the team about it.