Creating new payloads in Attack Simulation training

I am attempting to create new payloads for our staff to better replicate our international working environment and also the targeted emails we receive. I have options to view existing payloads but not create new ones. I'm a global admin and added the Attack Simulator admin as well just in case but the button to create new payloads isn't there. 

Is there a trick to this or is the functionality not available despite the help articles suggesting otherwise? If it has any impact, I'm on MacOS and Chrome (all patched to latest).