How to be authenticated when taking the incoming data stream and post it to an HTTP endpoint?

I created a tick script to take the alert data and post it to an HTTP endpoint. The kapacitor log showed an authentication error (http return code 401):

ts=2023-07-20T19:45:32.162Z lvl=error msg=“POST returned non 2xx status code” service=kapacitor task_master=main task=Ping_vm_mobility-os node=http_post7 err=“{\n "message": "You must be authenticated.",\n "status": 401\n}\n” code=401

To configure authentication for HTTP API within my TICKscript, I use the .header() method to add custom headers (user ID/password) to the HTTP POST request. The tick script code associated with this is listed below. Note that “m00591@dcae.att.com” is the user ID and its password is “Test00591”. They are added to ‘.header()’ for authentication:

var trigger = data
|alert()
.warn(lambda: (“value” >= warn_ppl AND “state_duration_ppl” >= 3) OR (“value2” >= warn_arm AND “state_duration_arm” >= 3))
.crit(lambda: (“value” >= crit_ppl AND “state_duration_ppl” >= 3) OR (“value2” >= crit_arm AND “state_duration_arm” >= 3))
.stateChangesOnly()
.message(message)
.details(‘’)
.id(‘{{ index .Tags “url” }}/Ping_vm_mobility-os’)
.idTag(idTag)
.levelTag(levelTag)
.messageField(messageField)
.durationField(durationField)
.log(‘/var/log/Ping_vm_mobility-os.log’)
|httpPost(‘http://fmsys-cambria-service-lb1.saapp-ueb.svc.cluster.local:3904/events/24256_MOBILITY_OS_EVENTS’)
.header(‘Authorization’, ‘m00591@dcae.att.com:Test00591’)
.captureResponse()

It looks like there is a problem when adding authentication information to HTTP POST header using ‘.header()’. What is the correct syntax/format in ‘.header()’ for this purpose? Or, how to configure authentication for HTTP API within my TICKscript?