You should send your log in ADIF format to the national coordinator or logmanager of the country where you activated the nature park. See a list of coordinators/logmanagers at WWFF National Programs. Make sure you add photographic proof of your activity using pictures of a GPS device (car navigation for example), park signs and your set-up. The national coordinator will make sure that your log is validated and added to the WorldWide Flora & Fauna log database, called logsearch.
If you activated a park in a DXCC that is not covered by the WWFF National Programs, then you can send your log to Manfred: DF6EX    wwfflogs@winqsl.de

Q: What log formats are supported?

A: ADIF or .CSV

Q: How should I name the log file?

A: {callsign} @ {reference} {date}.{extension}

• {callsign} is the callsign used
  Note: use hyphens ‘-‘ in place of the slashes ‘/’
• {reference} is the reference activated
• {date} is the date of the activation in ISO date format YYYYMMDD
  For multi-date activations, this should be the first day of activity.
• {extension} is ADI/ADIF or CSV

eg: M0YMA-P @ GFF-0354 20191209.ADI

Q: How do I specify the operator callsign?

A: The following fields should be used:

• STATION_CALLSIGN – the callsign used on the air by the activating station
• OPERATOR – the home-call of the individual operator who made the QSO

Q: How do I specify the WWFF reference?

A: The following fields should be used:

• MY_SIG should specify “WWFF”
• MY_SIG_INFO should specify the WWFF reference

For legacy, MY_SIG may be used to specify the reference.

Q: How do I specify the Hunter WWFF reference (for the Park 2 Park Award)?

A: The following fields should be used:

• SIG should specify “WWFF”
• SIG_INFO should specify the Hunter WWFF reference

Q: What other ADIF fields are required?

A: The following ADIF fields are required:

• CALL – the full callsign of the hunter
• QSO_DATE
• TIME_ON
• BAND
• MODE

All other fields are ignored.

WWFF offers activators a custom made simple logging software  : FLE WWFF-logger