i want to create the field of error :

[Joycetran]

create the field "DM Call errors #" ,
then count this number.
I tried to use case, but I dont have the field as title to match

[jpolvino]

If you're trying to create a new field for the DM Call Errors that contains the count for each event, then this is one way to do it:

(your search here) | rex "DM Call  errors #  : (?<DmCallErrors>\d+)"

Then you can add then up the field values using

| stats count(DmCallErrors) AS "Count of DM Call Errors"

somewhere after the extract.

If you and others need this, talk to your Splunk admin about having this field created when the log gets ingested, so you won't have to worry about the rex.