Could not find module "@angular-devkit/build-angular" from "/Downloads/Angular10/blog". code example

Example: Could not find module "@angular-devkit/build-angular

ng update @angular/cli @angular/core

If you are updating from angular 7 to angular 8 then do this

ng update @angular/cli @angular/core
for more information read here https://github.com/just-jeb/angular-builders/blob/master/MIGRATION.MD