How to get nvim-dap to attach to debugpy on continue()?

[dusktreader]

I am trying to configure nvim-dap to attach to a running debugpy instance when the continue() function is called. However, it seems to be ignoring my dap.configurations.python altogether.

Config looks like this:

return {
  "mfussenegger/nvim-dap",
  opts = {},
  config = function(_, opts)
    -- This plugin doesn't use setup() for some reason
    local dap = require("dap")
    dap.set_log_level("DEBUG")
    dap.configurations.python = {
      {
        type = 'python',
        request = 'attach',
        host = '127.0.0.1',
        port = 5678,
      },
    }
  end
}

But, when I run: :lua require('dap').continue(), I am immediately prompted for a configuration. I then have to select attach and then provide the host and port.

I really want this to work with one command triggered by a keymap. What am I doing wrong?