Probably not in the way you’re thinking.
By that I mean, it’s not possible for your Blink cam to be listed as a motion sensor in the ST app that can be selected as a trigger for an SHM alert. The now-defunct integration made that possible, but alas it’s gone (and probably never coming back IMO).
You can create an IFTTT applet such that if a Blink cam detects motion, it could activate a siren directly in ST. But that wouldn’t give you the other features of an SHM alert, like a push/SMS notification, lights turning on, red alert on the dashboard in the mobile app, etc.
Another option is to create a virtual switch, then have the IFTTT applet turn on that virtual switch when the Blink cam detects motion. Then you create a routine that’s triggered by the virtual switch, with various actions that could mostly replicate what happens when an SHM alert is triggered.
None of that is ideal, but with virtual switches especially, IFTTT sort of allows you to get various jobs done with Blink and ST.