Hi! I feel like I am missing something very obvious but have hit a wall so I thought it would be good to ask the community. I am trying to create automation that uses Jira Account ID's (key for the look up table) and our Slack User ID's (value for the look up table). Everything is working great until I introduce custom fields into the mix which is the critical thing for the use case I'm trying to solve for.
Use Case: Our Technical Writing team needs to notify content reviewers in Slack (our primary means of communication) when documentation is ready for review. We ship quickly and want these reviews to happen relatively quickly which is why the Slack message in important.

When I utilize the Send Slack Message Automation, the following produces the expected result.
Hello world @alex.galler
Hello world {{SlackName.get(issue.assignee)}}
If I attempt to use a custom field from our project instead of a system field, the message doesn't come through as I'd expect to see (the value just comes through as null). I've tried loads of different combinations but still no dice.
Hello world {{SlackName.get(issue.Primary Content Reviewer)}}
Hello world {{SlackName.get(issue."Primary Content Reviewer")}}
Hello world {{SlackName.get(issue.Primary Content Reviewer.accountId)}}
Hello world {{SlackName.get(issue."Primary Content Reviewer".accountId)}}
Hello world {{SlackName.get(issue.cf[123456].accountId)}}
etcHere is a screenshot of the automation workflow I am using for testing purposes:

Would appreciate any help! Thank you!