A JavaScript File Do Not Show in List on Online Customer Form

To resolve this, follow the steps below:

1. As Administrator navigate to Documents > File > SuiteScripts.
2. Edit the JavaScript file and check Available Without Login.
3. Click Save.
4. Navigate to Setup > Marketing > Online Customer Forms.
5. Edit any Online Customer Form > Custom Code > Hit the (>>) button > List > Notice the SuiteScript file is now showing.
 
Note: Per Field Level Help, Check this box if you want this file accessible externally. The file may be accessed with a URL that points to the file record. Clear this box if you want the file only accessible to those who are logged in to NetSuite with permission to view file cabinet documents.