You must first install CustomJS npm package, which contains all CustomJS modules for n8n. The package is available on npmjs at @custom-js/n8n-nodes-pdf-toolkit. This is a community package natively supported by n8n.
Make sure your n8n version supports Community Nodes (>= v0.187.0).
Alternatively, you can install the community package directly from the n8n editor:
Open your self-hosted n8n instance in the browser.
Go to Settings > Community Nodes.
Click on Install a Community Node.
Enter the package name: @custom-js/n8n-nodes-pdf-toolkit, confirm you understand the installation risk, and click Install.
Package Installation
Confirm and restart n8n if prompted. After installation, all CustomJS nodes will be available in the node selector.
CustomJS Nodes
If the node does not appear, reload the n8n editor UI.