Yes, you are entitled to claim for payments under the Statement of Financial Entitlement (SFE) if you're not in the NHS Pension Scheme as long as you're not incorporated (i.e. a Limited Company Performer). 

Maternity, paternity and long-term sickness are calculated against your Net Pensionable Earnings Equivalent (NPEE) figure. You must ensure you have the correct Net Pensionable Earnings Equivalent (NPEE) amount against your performer record on Compass otherwise no payments can be made.

If a change to your NPEE is required, speak to your provider who can then update this on Compass.