Module not found: Can't resolve 'core-js/library/fn/reflect/es7/metadata' code example

Example 1: Module not found: Error: Can't resolve 'core-js/modules/es6.object.create

solution install core-js@2.6.5

Example 2: Module not found: Error: Can't resolve 'core-js/client/shim'

import 'core-js/es/symbol'