Thanks for reaching out to us regarding this ask. Based on the details provided, I think the issue here is that F5 doesn't have license expiration but rather Service Checks. You can search rules by device type, F5 devices for example, locate 'Service Check Approaching' then configure from there. Please note that this rule will not trigger an event before the relevant date is reached. One method I've seen that worked well for others was to create a rule that triggers a warning at 90 days before expiration, and then a Critical message if it's 20-30 days before requiring service. I've attached examples of how to search for rule by device type.
SEARCHING RULES BY DEVICE
SEARCHING RULE BY NAME - NOTICE DEVICE TYPE IN RULE OVERVIEW > CATEGORY
Please let me know if you have any additional questions.