Based on what I did, If you can see the send button active, I selected my App Name Under App... And Selected iOS (in my case) under Platform. The above details as seen in the screenshot were greyed out with my related details already.
And then I hit send button. My expedited review request instantly approved to read " We will expedite review your ....app ...I screenshotted the result. But sadly, I didn't received any email. It did not trigger outbound email.
I am still waiting and no joy after this. It's not flipped to In Review." Yet. It's been more than 48 hrs since my expedited review request (19th Feb) was approved.
This is what I am going through hope all goes well at your end. This is just for your info, and this is what I done. I could be wrong about what I have done so far🙏