How can find specific string in files that are rotating

[bab]

I was read about logrt to find specific string in the files but could not find out some parts.
I want to find specific string in my files that are rotating by size :
My path file is : /usr/local/card/log/card/
My string that I am looking for that in the files : "Connection is not available"
My files that are generating :
card-2024-12-30_0.log
card-2024-12-30_1.log
card-2024-12-30_2.log
card-2024-12-30_3.log
card-2024-12-30_4.log
card-2024-12-30_5.log
card-2024-12-30_6.log
.
.
I know have to use zabbix agent(Active)
key = logrt

Would you please help me how should fill follow key for that ?
logrt[file_regexp,<regexp>,<encoding>,<maxlines>,<mode>, <output>,<maxdelay>,<options>,<persistent_dir>]

[kyus]

Hey!

I think that you can use the following key:

logrt["/var/log/zabbix/card.*","Connection is not available"]