How to Create Email Alert in FortiAnalyzer if Forticlient VPN Users Exceed Threshhold

HI Team,

we installed Fortianaylzer and want to generate Email Alert if Forticlient Users exceed by 100 numbers. can somebody help me to guide how to create Email Alert if forticlient Users Exceed (we want if 100 Users access via Forticlient then we should get Email Alert)

FortiAnalyzer Version is 6.0.8

Thanks in Advance

Hashim