Updates for this Mac are managed externally. Do you want to restore default update settings?

Elifetrends wrote:

This is my personal MAC Pro.

Did you buy the computer used? If so, it may be challenging to remove the external management control if what D.I. Johnson suggested does not work.

Managed computers can come that way out of the box new, in which case if you obtained it later from another party you would need Apple's help to remove this. If it was imposed later by a company, that company can remove it.

This sounds to me like the Mac is being managed by an IT manager or group. If this is a business machine on loan to you, check with your boss.

If it's your personal machine, restore the default update settings.

This is my personal MAC Pro.