No. The Canon PowerShot SX70 HS does not appear to offer a bulb mode, so you cannot set the shutter to bulb on this camera.

This is common with many small-sensor bridge/compact cameras, which often limit maximum exposure time to reduce image quality problems caused by sensor heat during very long exposures. In practice, that means the camera is restricted to its built-in long-exposure limits rather than allowing an open-ended bulb setting.

If you need exposures longer than the camera’s maximum shutter time, you would need a different camera model that specifically supports bulb mode or extended manual exposures.