GitHub Copilot can use a user-defined prompt to generate commit messages. To set it up, you can configure the github.copilot.chat.commitMessageGeneration.instructions in your settings.json file like this:

{
  "github.copilot.chat.commitMessageGeneration.instructions": [
    {"text": "Write a concise commit message starting with a change tag"},
  ]
}

Or, you can use a template file. To do this, create a file, for example, commit-message-template.md, and set it up:

{
  "github.copilot.chat.commitMessageGeneration.instructions": [
    {"file": "commit-message-template.md"}
  ]
}