Request and download filename sdk3.tgz, which requires Andor approval to download limited time. Extract and run:

tar xf *sdk3*.tgz
bash install_andor

You may need to make manual changes to ~/.profile and /etc/rc.local as per doc/ Then try fast simple cross-platform example Andor sCMOS C++14 code for Andor SDK3.

Related: Install Andor sCMOS SDK3 in Windows