I am utilising the System -> External System Import -> CSV function.
I am attempting to import issues that I exported from another JIRA cloud instance.
The CSV contains a Custom Field (Story Points) column, which has numerical values.
When attempting to import the CSV file, the mapping dropdown does not have a `Story Points` option. This means I cannot map the story points over.
The Story Points field is present on my create / edit issue views for this project.
I had to set the applicable issue types to "Any issue type".
Also ensure that you are importing via System -> External System Import -> CSV as importing from the issue explorer doesn't appear to allow mapping of many of the fields (for reasons I don't know).