Please wait for some seconds, after redirecting to your wallet for some background verification before the connect button appears, then you wait for some seconds before it redirects back to Binance FX website.
Please don't click anything before the connect button appear, or the the pop up appear, to avoid disrupting the background verification and not seeing the connect button.

Please if after several attempts and you don't see the connect button or pop up, please try another wallet or report the issue to Binance FX to resolve the issue.

Thanks
Binance FX Team