How to upgrade from Catalina on MacBook Pro 15”

Catalina. See the following from Identify your MacBook Pro model - Apple Support

MacBook Pro (Retina, 15-inch, Mid 2012)

Model Identifier: MacBookPro10,1

Newest compatible operating system: macOS Catalina 10.15.7

Tech Specs: MacBook Pro (Retina, 15-inch, Mid 2012)

User Guide: MacBook Pro (Retina, 15-inch, Mid 2012)

MacBook Pro (15-inch, Mid 2012)

Model Identifier: MacBookPro9,1

Part Numbers: MD103xx/A, MD104xx/A

Newest compatible operating system: macOS Catalina 10.15.7

carolfrommemphis wrote:

MacBook Pro 12". Mid 2012

There is no 12" MacBook Pro Mid 2012. There are 13" and 15" models and the last possible upgrade for any of them is Catalina.