The GoPro Studio's version is 18.104.22.16843, therefore the GoPro Support is right. You can use the link posted below to download the installation package. However, the new name of the application is Quick and you can install it free of charge.
Important note: After some additional searching I've found that these two apps have the same meaning, only that GoPro Studio has been retired and indeed its version was 2.5.7. Unfortunately, that version is no longer accessing, that's why support redirected you to the Quick version that is actually 2.1