How to round corners on a text box in Apple Pages?
I'm using Apple Pages on my MacBook Pro, running macOS Sonoma 14.5 and Apple Pages v14.1. I've recently started to use text boxes. Today I said, well, let's see what that looks like with rounded corners... and then I spent ~45 minutes trying to find the controls for that. I've looked for advice online, and often I'm not seeing what the instructions describe. Then a couple times I've managed to come across a screen that has a "rounded corners" selection, but the checkbox and description are grayed out and so that can't be selected. TIA for any thoughts about this.
MacBook Pro 14″, macOS 14.5