The problem with getting the value of a field for task found using lookup

[Oksana Baier]

We use Release Container (Story) which have relation with all released tikets
Release Story and release tickets have the same FixVersion
FixVersion and Release Story have the same name
Release Story have label RELEASE

What I need:
Close release in Jira, when last ticket with FixVersion is Done
But with fill Release Date from Release Story

I make jira rule

Trigger:
- ticket moved to Done

Condition:
- fixVersion is not empty


lookup "fixVersion = "{{issue.fixVersions.name}}" AND statusCategory != Done"

If {{lookupIssues.size}} egual 0

Actions:

1 lookup "labels = RELEASE AND type = Story AND fixVersion = "{{issue.Fix versions.name}}""

2 Create variable: ReleaseDate = (smart value) {{lookupIssues.0."Release date"}}

3 Release version: {{ReleaseDate}}

What problem

- Create variable: ReleaseDate = (smart value) {{lookupIssues.0."Release date"}} - is not work(

In 1 action I see one task - Release Story
I need value of a field for this task
I found in internet {{lookupIssues.0."Release date"}}
But it is doesn't work