I have a website site1.com that has an iframe with code coming from site2.com. This iframe contains a registration form. When I try to submit the form, I get the error "Session expired or cookies are not enabled in your browser. Please press "reload page" in your browser, and enable cookies in your browser." I know that I need to set samesite=none, secure=true" SOMEWHERE, but after reading tons of articles, I can't figure out where. I've added document.cookie = "samesite=none, secure=true"; to the page on my hosting site site1.com, and on the page from site2.com that is in iframe, but nothing is changing the error. Any suggestions?