This is how to perform an ftp list command using net.ftp.list from the net module.
This example uses a publically available test server, which is enabled for list and get only.
Here is the code for you to copy:
function main() local id=net.ftp.init{ server='ftp.secureftp-test.com', username='test', password='test'} id:list{remote_path='/'} id:list{remote_path='/subdir1'} end