I'm afraid you can't. Explaindio Video Bundle 2020 PRO Upgrade is an Upgrade package for Explaindio Video Bundle 2020 only. Even if you somehow able to purchase the PRO Upgrade without buying the Explaindio Video Bundle 2020, you wouldn't be able to use these products without the main products which comes with Explaindio Video Bundle 2020.
However, if you already have any of the products in your account you will be able to get an upgrade of those existing products only in your account. But buying Explaindio Video Bundle 2020 PRO Upgrade without the main package will not add access to the main package products in your account.
So, if you bought PRO without the main package, you should hurry and buy the Explaindio Video Bundle 2020 before this deal is closed.