Logpush - "logpull_options" Select all fields

Can you please tell me how I can configure the “logpull_options” → fields
to select ALL the fields through API?
I have tried the following:

“logpull_options”: “fields=ALL_Fields&timestamps=rfc3339”
“logpull_options”: “fields=all&timestamps=rfc3339”
“logpull_options”: “fields=All&timestamps=rfc3339”