update

Hello~ You cannot update your iPad mini 2 beyond iOS 12.5.3. . You can go up to the black line at top of this page click on iPad and do some shopping for a new iPad if you need current iOS. I have an iPad 8th gen and love it. Also take a look here:

Apple - Official Site

~Katana-San~

end of the line is

iPad Mini 2 - Wikipedia

Current: iOS 12.5.4, released June 14, 2021[1]

have you read

Update your iPhone, iPad, or iPod touch - Apple Support

Hello ~ Could you provide the model details of your iPad?

Identify your iPad model - Apple Support

~Katana-San~