Optional - Sets the SameSite flag.

Values:

• "Strict" - (default) cookies are sent only on the host site.
• "Lax" - cookies are sent to the host site and to any other site that requests the HTML page, but not related links (ie. images)
• "None" - cookies are sent to the host site and any other site that requests a resource. If you use this setting and are not setting the Secure cookie only the browser will give a warning or fail to send the cookie (not recommended any longer)
• Empty - no same site policy (not recommended )

More info on SameSite cookie can be found here.

o.SameSite