If you are still using Copilot, I made a VSCode extension that adds Claude 3.5 Sonnet and possibly other models to the GitHub Copilot chat. The additional models are available as chat participants. Type the @ symbol and select the model you want to use.

You need your own API key (BYOK) - this is not covered by GitHub Copilot subscription.

It's still in early development, so if you try it out and run into any issues, let me know. I'd love to hear your thoughts and suggestions too!