If you want to restrict participation to certain devices, you can indicate that only Desktop, Mobile, or Tablet devices are allowed in the Study Details section when creating your study. In this section, you can also specify if your study requires audio, a camera, a microphone, or downloading software.
Participants will then see this information before they choose part in your study, allowing them to make an informed choice as to whether they'd like to participate.
It's worth noting that these options do not screen out participants based on the device options you select.
However, if you indicate specific device compatibility for your study on Prolific (e.g. desktop-only) and state this requirement in your study description, submissions from participants who take part using an unsupported device do not require approval.
If you'd like to ensure participants only use a certain type of device (e.g. desktop), some survey software allows you to restrict participation in this way.
For instance, Qualtrics offers this functionality, and can be set up using display logic and restricting to device type. Gorilla also support restriction of studies to specific device types. There is further guidance on how to set this up here.