Override time value for Server Performance Exception - APM

Hi,

I have APM alerts which name is "Server Performance Exception". The alert rule is "Generate Alert for Performance APM Event". The alert description is " '/Frame.aspx' has exceeded the configured threshold 60000 ms on: myserver.mydomain.net. For additional details please use the following link: http://..."

I need to increase the 60000 ms value, but when I open the alert rule properties, the parameters are: Enable, Priority and Severity. Nothing about time threshold.

The question is:

How to override the value (60000 ms) stated at the alert description?

Thanks in advance!