I have read through NWebSec's documentation to try and resolve the problem.
Set the web.config
to
<nwebsec>
<httpHeaderSecurityModule
xsi:noNamespaceSchemaLocation="NWebsecConfig/HttpHeaderSecurityModuleConfig.xsd"
xmlns="http://nwebsec.com/HttpHeaderSecurityModuleConfig.xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<redirectValidation enabled="false">
<allowSameHostRedirectsToHttps enabled="false"/>
<add allowedDestination="https://www.facebook.com/"/>
<add allowedDestination="http://www.nwebsec.com/"/>
<add allowedDestination="https://www.google.com/accounts/"/>
</redirectValidation>
<securityHttpHeaders>
<strict-Transport-Security max-age="365" includeSubdomains="true" httpsOnly="false" preload="true" />
</securityHttpHeaders>
</httpHeaderSecurityModule>
but I am still getting
A potentially dangerous redirect was detected. Add the destination to the whitelist in configuration if the redirect was intended. Offending redirect: https://www.facebook.com/dialog/oauth?response_type=code&