: Ensure you need Distributed Safety (for S7-300F/400F) and not S7 F-Systems (for PCS 7) or STEP 7 Safety Advanced (for TIA Portal). If you'd like, I can help you: Find the exact part number for purchasing a license.
: It supports safety requirements up to SIL3 (IEC 61508) and Performance Level (PL) e (ISO 13849-1). Simatic S7 Distributed Safety V5.6 Download