MXToolbox
Trigger: !spf
Try it
Kagi would openhttps://mxtoolbox.com/SuperTool.aspx?action=spf:nginx+reverse+proxy&run=toolpage
Run @spf in Kagi for Kagi's own results from mxtoolbox.com only
URL pattern: https://mxtoolbox.com/SuperTool.aspx?action=spf:query&run=toolpage
Searches mxtoolbox.com, filed under Sysadmin.