ローカル開発環境の構築 [macOS編] - プログラミングならドットインストール

上記ページを参照して#06の「仮想マシンを立ち上げよう」まで進んだのですが、

~/MyVagrant/MyCentOS$ vagrant up
No usable default provider could be found for your system.

Vagrant relies on interactions with 3rd party systems, known as
"providers", to provide Vagrant with resources to run development
environments. Examples are VirtualBox, VMware, Hyper-V.

The easiest solution to this message is to install VirtualBox, which
is available for free on all major platforms.

If you believe you already have a provider available, make sure it
is properly installed and configured. You can see more details about
why a particular provider isn't working by forcing usage with
`vagrant up --provider=PROVIDER`, which should give you a more specific
error message for that particular provider.

というエラーが出てしまいます。
Virtualboxは、6.0.6、vagrantは、2.2.4をインストールしました。

どうすればエラーを解消できるでしょうか。