I bought a this extension from marketplace.magento.com. I tried to install it via composer like this:
composer require bsscommerce/customer-approval
But I get
(InvalidArgumentException) Could not find a matching version of
package bsscommerce/customer-approval. Check the package spelling,
your version constraint and that the package is available in a
stability which matches your minimum-stability (stable).
I also followed this documentation, but it does not help.