The DL533R is a PC/SC conformant reader, which means it acts a a smartcard reader for the OS.
What you actually transmit and what smartcard / chip (Apex or FlexSecure) you use, is up to you.
I recommend reading flexsecure-applets/docs/1-technology.md at master · DangerousThings/flexsecure-applets · GitHub , and having a look at the applet list at Apex Platform - VivoKey Technologies and documentation in flexsecure-applets/docs/applets at master · DangerousThings/flexsecure-applets · GitHub .