How should I Store Application Passwords in Jmeter Scripts used in ASM?
ASM users are encouraged to store application passwords for Jmeter scripts directly in the “User Name” and “Password” fields present on the monitor configuration screen (Settings ? Monitors ? <Monitor Name>). Inside the Jmeter script, variables can be used to represent both the username and password. These variables ${__property(WMaccount)} and ${__property(WMpasswd)} respectively. These values should be placed in an Http Authorization Manager. For example:
Additional References on this topic can be found here.