Stage manager not appeare in my device

Due to limitations of internal hardware, the Stage Manager feature introduced with iPadOS 16.1 is only available for these models of iPad:

• iPad Air (5th generation)
• iPad Pro 11-inch (all generations)
• iPad Pro 12.9-inch (3rd generation and later)

Feature availability is usually limited by system hardware - CPU and available RAM being critical to some advanced functionality.

iPad models supporting Stage Manager have an M2, M1 or A12X CPU (upon which the M-series CPUs are reportedly based) - with at least 8GB RAM. The iPad Air4, by example, has only 4GB RAM.

Whether or not a functionally limited version of Stage Manager, compatible with models of iPad that do not meet the current hardware requirements, will ever be released is unknown.

It looks like Stage Manager is only available for the 5th generation iPad Air, and not for any older models.

Turn Stage Manager on or off on your iPad - Apple Support

iPad models that support Stage Manager

You can use Stage Manager on these iPad models:

iPad Pro 12.9-inch (3rd generation and later)

iPad Pro 11-inch (1st generation and later)

iPad Air (5th generation)

Which iPad do you have?

~Lyssa