Even if this can be integrated, it would be a cloud based integration subject to change at the whims of the manufacturer, and could even be shutoff at anytime.
Examples of people being left in the cold by cloud based API changes include Tuya Revert back to the old way of handling Tuya please - #28 by balloob , Insteon Is Insteon Dead? - #2 by mwav3 , and TPLINK TP-Link HS110 Smart Plug disappears after latest firmware update
I would not rely on an online integration using an API for something as critical as a smoke alarm activating. Actually, I wouldn’t rely on cloud based integrations for anything anymore as I’ve been burned too many times by them failing.
Instead, you might want to look at this option to make your existing detectors smart and use Zwave, an entirely local and standard protocol. If they are wired and interconnected you would only need one relay and can keep your existing detectors.