Install alpha-nvim problems in neovim using vim-plug

here is my error display

   Error detected while processing /home/cuiem/.config/nvim/init.vim:
   line   10:

    E5108: Error executing lua [string ":lua"]:1: module 'alpha' not found:

    no field package.preload['alpha']
    no file './alpha.lua'
    no file '/usr/share/luajit-2.1.0-beta3/alpha.lua'
    no file '/usr/local/share/lua/5.1/alpha.lua'
    no file '/usr/local/share/lua/5.1/alpha/init.lua'
    no file '/usr/share/lua/5.1/alpha.lua'
    no file '/usr/share/lua/5.1/alpha/init.lua'
    no file './alpha.so'
    no file '/usr/local/lib/lua/5.1/alpha.so'
    no file '/usr/lib/x86_64-linux-gnu/lua/5.1/alpha.so'
    no file '/usr/local/lib/lua/5.1/loadall.so'
    stack traceback:
    [C]: in function 'require'
    [string ":lua"]:1: in main chunk

here is my code in init.vim

  call plug#begin('~/.local/share/nvim/site/plugged')  
   2 Plug 'bling/vim-airline'
   3 Plug 'jiangmiao/auto-pairs'
   4 Plug 'folke/tokyonight.nvim'
   5 Plug 'scrooloose/nerdtree'
   6 Plug 'goolord/alpha-nvim'
   7 Plug 'kyazdani42/nvim-web-devicons'
   8 lua << EOF
   9 require'alpha'.setup( require'alpha.themes.startify'.config, require'nvim-web-devicons'.setup() )
  10 EOF
  11  
  12 Plug 'lervag/vimtex'
  13 let g:tex_flavor='latex'
  14 let g:vimtex_view_general_viewer = 'zathura'
  15 let g:vimtex_view_method='zathura'
  16 let g:vimtex_quickfix_mode=0
  17 set conceallevel=1
  18 let g:tex_conceal='abdmg'
  19  
  20 call plug#end()
  21  
  22 syntax on
  23  
  24 set nu
  25 set cursorline
  26 set autoindent
  27 set showmatch
  28 set smartindent
  29 set encoding=utf-8
  30  
  31 let g:auto_save = 1
  32  
  33 " ###################### 设置主题外观 ####################
  34 set background=dark
  35 set cursorline
  36 set cursorcolumn
  37 colorscheme tokyonight

goolord / alpha-nvim

Install alpha-nvim problems in neovim using vim-plug #244