Change find engine "on demand"

[lukepass]

Hello, is it possible to change the find engine "on demand" (I need to use ag instead of rg for one specific case). My current configuration is the following:

return {
  'nvim-pack/nvim-spectre',
  dependencies = { 'nvim-lua/plenary.nvim' },
  config = function()
    vim.keymap.set('n', '<leader>S', '<cmd>lua require("spectre").toggle()<CR>', {
      desc = 'Toggle Spectre',
    })
    vim.keymap.set('n', '<leader>rw', '<cmd>lua require("spectre").open_visual({select_word=true})<CR>', {
      desc = 'Search current word',
    })
    vim.keymap.set('v', '<leader>rw', '<esc><cmd>lua require("spectre").open_visual()<CR>', {
      desc = 'Search current word',
    })
    vim.keymap.set('n', '<leader>sp', '<cmd>lua require("spectre").open_file_search({select_word=true})<CR>', {
      desc = 'Search on current file',
    })
  end,
}

Thanks.