You can sign up for emergency satellite texting if you have a phone compatible with T-Satellite, though there are some pretty notable exceptions. It doesn't support phones with emergency satellite texting built in, including the iPhone 14 and later, as well as the Pixel 9 and up (excluding the 9A). That means you can only use T-Mobile's 911 texting if you have an iPhone 13, Pixel 9A, a Samsung Galaxy S21 and up, or a newer Motorola phone.
The final general release for iPadOS 26 and iOS 26 is slated for September 15. Apple released the developer beta of iPadOS 26 for registered developers during WWDC in June. The public beta is available now, giving anyone early access to test it. Which iPads are compatible with iPadOS 26? You'll need an iPad with iPadOS 16.4 or later, which means one of these models: iPad Pro (M4) iPad Pro 12.9-inch (3rd generation or later)