The following steps will help you import your notes from Standard notes easily.
Preferences icon on bottom left corner to open preferences.
Data backups section and choose backup type
Backups from the Sidebar & select “Data backup” to download backup .zip file.
Standard Notes from list of apps.
.zip file, go to Notesnook app > Settings > Notesnook Importer and click on “Import from ZIP file” & select the .zip you downloaded earlier.