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.