It seems like that part of the site may not be used anymore? When I login as a technology partner, I see the link to the downloads for the 2022 R1 MIP SDK and redistributables at https://www.milestonesys.com/my-milestone/application-track/
The SDK installer can be downloaded from http://download.milestonesys.com/MIPSDK/MIPSDK_Installer_2022R1.msi and going forward, the docs are online, the samples are on github and can be forked/cloned, and the binaries can be added to your project as nuget package references.