Steps to reproduce:

1. in Jira disable basic auth for API calls in Administration > System > Authentificationmethods > Authentication
2. in Zabbix configure Jira Service Management media type template with the corresponding values for:
   • jira_password: enter personal access token for a Jira user
   • jira_request_type_id: as required
   • jira_servicedesk_id: as required
   • jira_url: as required
   • jira_user: Jira user to use
3. Click on "Test" for the configured media type

Result:

Media type test failed:

Sending failed: Unknown error. Check debug log for more information

Log output shows the following error:

00:00:00.022 [Debug] [Jira Service Management Webhook] Response has been received: {"message":"Die Standardauthentifizierung wurde in dieser Instanz deaktiviert."}00:00:00.022 [Warning] [Jira Service Management Webhook] HTTP code: 40300:00:00.022 [Warning] [Jira Service Management Webhook] Request not successful. Received response: {"message":"Die Standardauthentifizierung wurde in dieser Instanz deaktiviert."}

The message "Die Standardauthentifizierung wurde in dieser Instanz deaktiviert." means: "Basic authentication has been disabled in this instance."
Expected:
Media type test succeeds regardless of basic authentification oder personal access token usage

Possible cause/solution:

This error seems to be caused by line 577 of Jira Service Management (Jira: 573) template:

this.request.addHeaders('Authorization: Basic ' + btoa(this.params.jira_user + ':' + this.params.jira_password)); 

for Personal access token usage this must be:

this.request.addHeaders('Authorization: Bearer ' + this.params.jira_password); 

Maybe the best solution might be an additional paramter for the templates which allows an selection of the authentication method to use like jira_auth_type with valid values of 0 (basic auth) or 1 (bearer/pat auth) and a switch which selects the corresponding of both mentionend authentication headers.

Currently I hard coded/updated all Authorization headers in the templates to use Bearer token.