Yes. The K-50 can use an external intervalometer/timer remote through its wired remote shutter input. Since one press of the shutter can trigger the full 3-frame bracketed burst, a timer remote that sends a shutter press every 10 seconds should let you create an HDR timelapse.

Community members reported success with intervalometer remotes such as the Phottox TR-90, and also with generic timer remotes that fit cameras using a 2.5mm stereo mini-plug. Dynamic Perception controllers were also mentioned as working with Pentax bodies via the remote control jack.

So the practical thing to search for is a Pentax-compatible wired intervalometer/timer remote, especially one using the 2.5mm remote connection. Just confirm the connector matches your K-50 before buying.