You can include it from the WSYWIG editor or use it on the following lines for Fragments{{!-- [acr-start-fragment] --}}{{ fragment id="ajo:99a6c063-511c-4871-87a8-00516a3a40b5" name="Luma Newsletter" mode="inline" }}{{!-- [acr-end-fragment] --}}Reference - https://experienceleague.adobe.com/en/docs/...

You will find it in the browser URL when you open the respective fragment or content template. FragmentExample - https://experience.adobe.com/#/@<tenant>/sname:dev/journey-optimizer/fragments/<fragmentId>/publications/99489f31-20ee-4bee-b4a5-969f20955d4b Content TemplateExample - https://experience....

Interesting, I see the expression validates fine. Can you add it from the expression editor and replace .at(0) with the relevant filters per the below example.  

Can you validate it on the following lines ?Example - in('<messageIdPlaceholder>',#{ExperiencePlatform.ajo_ds_email_received.experienceevent.all(inLastDays(currentDataPackField.timestamp,7))._experience. customerJourneyManagement.messageExecution.messageID})

Kindly submit an enhancement request for this ask with the details of the requirement and the client care team will revert back with the specifics.

You can disable the timeout / error transition and run the journey in test mode to see the error logs.

If this is a condition activity, you can alter it on the following lines sum( sum(#{ExperiencePlatform.ProfileFieldGroup.profile._tenant.Trigger.Triggers.all(currentDataPackField.triggerName=="trg_0079_loan_promise" and currentDataPackField.numericAttribute01>=5000).numericAttribute01}) , sum(#{Ex...

You can validate it on the following lines {%= substr(toString(<ReplaceWithAccountNumber>), length(toString(<ReplaceWithAccountNumber>))-4, length(toString(<ReplaceWithAccountNumber>))) %}

1) Yes, depending on the start dates - Also, take a look at this video https://experienceleague.adobe.com/en/docs/journey-optimizer/using/campaigns/get-started-with-campaigns#statuses 2) You can query the profile snapshot dataset for the respective audience Id to verify the correctness of the audien...

You can create web hooks or test end points (by using custom actions) to view the incoming event payload. If it is for debugging purpose, you can look at the test mode logs by running the journey in test mode.