How to install and config?

[ayamir]

I'm using packer.nvim to manage it, but error was met when I try using it. Following is the error: This is my config function for telescope:

function config.telescope()
    local home = os.getenv("HOME")

    if not packer_plugins['plenary.nvim'].loaded then
        vim.cmd [[packadd plenary.nvim]]
    end

    if not packer_plugins['popup.nvim'].loaded then
        vim.cmd [[packadd popup.nvim]]
    end

    if not packer_plugins['telescope-fzy-native.nvim'].loaded then
        vim.cmd [[packadd telescope-fzy-native.nvim]]
    end

    if not packer_plugins['telescope-project.nvim'].loaded then
        vim.cmd [[packadd telescope-project.nvim]]
    end

    if not packer_plugins['telescope-frecency.nvim'].loaded then
        vim.cmd [[packadd telescope-frecency.nvim]]
    end

    require('telescope').load_extension('fzy_native')
    require('telescope').load_extension('project')
    require('telescope').load_extension('frecency')

    require('telescope').setup {
        defaults = {
            prompt_prefix = '🔭 ',
            selection_caret = " ",
            layout_config = {
                horizontal = {prompt_position = "bottom", results_width = 0.6},
                vertical = {mirror = false}
            },
            file_previewer = require'telescope.previewers'.vim_buffer_cat.new,
            grep_previewer = require'telescope.previewers'.vim_buffer_vimgrep
                .new,
            qflist_previewer = require'telescope.previewers'.vim_buffer_qflist
                .new,
            file_sorter = require("telescope.sorters").get_fuzzy_file,
            file_ignore_patterns = {},
            generic_sorter = require("telescope.sorters").get_generic_fuzzy_sorter,
            path_display = {"absolute"},
            winblend = 0,
            border = {},
            borderchars = {
                "─", "│", "─", "│", "╭", "╮", "╯", "╰"
            },
            color_devicons = true,
            use_less = true,
            set_env = {["COLORTERM"] = "truecolor"}
        },
        extensions = {
            fzy_native = {
                override_generic_sorter = false,
                override_file_sorter = true
            },
            frecency = {
                show_scores = true,
                show_unindexed = true,
                ignore_patterns = {"*.git/*", "*/tmp/*"},
                workspaces = {
                    ["conf"] = home .. "/.config",
                    ["data"] = home .. "/.local/share",
                    ["nvim"] = home .. "/.config/nvim",
                    ["code"] = home .. "/code",
                    ["c"] = home .. "/code/c",
                    ["cpp"] = home .. "/code/cpp",
                    ["go"] = home .. "/go/src",
                    ["rust"] = home .. "/code/rs"
                }
            }
        }
    }
end

[ayamir]

It's my fault to forget to add

    if not packer_plugins['sql.nvim'].loaded then
        vim.cmd [[packadd sql.nvim]]
    end

to config.