Apple SIM technology is no longer available to activate new cellular data plans on iPads. The Apple SIM, first introduced by Apple in 2014, is a programmable SIM card that could be configured with different operator profiles, eliminating the need to buy a physical SIM from the carrier itself. The change was first spotted by MacRumors.
Apple quietly made the announcement via its cellular data support page, which says that support for new activations using both the standard Apple SIM and embedded Apple SIM would stop from October 1st, 2022. Apple recommends that anyone affected by the change should contact their carrier for details on how to activate a cellular data plan on their iPad.
The Apple SIM always seemed like a temporary solution
The Apple SIM first appeared as a physical nano-SIM card in the GPS + Cellular versions of the iPad Air 2 and iPad mini 3, and went on to be supported by additional iPad models since its release, including as an embedded SIM in later iPad Pro models. Supported carriers include AT&T, Sprint, and T-Mobile in the US, with additional carriers offered in other regions. You can check if your iPad supports Apple SIM by looking up the technical specifications of your iPad model on the Apple website. MacRumors notes that all models of the iPad Pro, iPad Air, iPad mini, and iPad released since October 2018 support eSIMs — so, no Apple SIM required.