Copilot returns "unsupported_api_for_model" error code

[dompuiu]

I am using LazyVim and I enabled the ai.avante extra. I am using the Copilot provider. I created an avante.nvim plugin with this config

return {
  {
    "yetone/avante.nvim",
    opts = {
      provider = "copilot",
      providers = {
        copilot = {
          model = "claude-sonnet-4.5",
        },
      },
      selector = {
        provider = "fzf_lua",
      },
      selection = {
        hint_display = "none",
      },
      behaviour = {
        auto_set_keymaps = false,
      },
      web_search_engine = {
        provider = "brave",
      },
    },
  },
}

When I try to use Avante I get this error:

Error: {
  code = "unsupported_api_for_model",
  message = "model claude-sonnet-4.5 is not supported via Responses API."
}

I tried to switch the models and same error appears.

Has anybody seen an error like this and have an idea of how to fix it?

Thank you in advance!