30 November 2020 is the last day you can submit claims for periods ending on or before 31 October 2020. After this date you will not be able to submit any further claims or add to existing claims. More here.
Further guidance on the Self-Employment Income Support Scheme grant extension
Guidance is available on how HMRC will work out your trading profits and non-trading income if you're self-employed or a member of a partnership and have been adversely affected by coronavirus. A video on how to claim the second grant step-by-step is also available.