If a girl from a dating site refers you to a broker, its a romance scam. Let me guess. You might be lucky enough to have gotten a voice message or two (maybe even a very short voice chat), but haven't had a video chat. Most/all communication has been by text. She was busy and asked you to talk to a broker and place some trades in her account. All of the trades were quickly and amazingly profitable. Now she wants you to experience the same success by opening your own account.
If a broker's site is http instead of https, it's an untrustworthy broker. A personal blog might be http. Any website that involves submitting your ID or financial information should always be https. mifoo's site is http.
miifoo.cn was registered a little over a year ago. There's nothing at miifoo.cn itself.
Despite this, they claim to have been in business for more than 10 years. You can see a nearly identical site at cc-forex.com (registered on May 20, 2020).
Report the girl to Tinder. You went there for a date, not to invest with a broker that has a barely functional website.