not an .xlsx file
Use the file LinkedIn downloads; do not convert it.
available in LinkedIn Analytics Report Pro
That option is part of Pro; run without it.
Claude does not use the skill
Check it is switched on in Settings → Capabilities → Skills, then name it in your message.
The script says a column is missing
Rename your header to one of the names in README, or say the mapping in your message.
Code execution is off
Skills with scripts need code execution enabled in Claude.ai settings.
FAQ
Where do I get the export? On a computer: click Post impressions under your name on the LinkedIn home page, choose a date range, press Export and Confirm.
What does Pro add? Comparison with an earlier export, follower gains after posts, quadrants, your own tags, audience match and charts.