E492: Not an editor command: MarkdownPreview

I can’t preview my markdown files

My vim config

nvim --version:

NVIM v0.4.2
Build type: Release
LuaJIT 2.0.5
Compilation: /usr/bin/cc -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -O2 -DNDEBUG -DMIN_LOG_LEVEL=3 -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fdiagnostics-color=always -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/build/neovim/src/build/config -I/build/neovim/src/neovim-0.4.2/src -I/usr/include -I/build/neovim/src/build/src/nvim/auto -I/build/neovim/src/build/include
Compiled by builduser

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/share/nvim"

Run :checkhealth for more info

:checkhealth :

health#coc#check
========================================================================
  - OK: Environment check passed
  - WARNING: pyx command not work, some extensions may fail to work, checkout ":help |pythonx|"
  - OK: Javascript bundle found
  - OK: Service started

health#mkdp#check
========================================================================
  - INFO: Platform: linux
  - INFO: Nvim Version: NVIM v0.4.2
  - INFO: Pre build: /home/tozkoparan/.vim/plugged/markdown-preview.nvim/app/bin/markdown-preview-linux
  - INFO: Pre build version: 0.0.9
  - OK: Using pre build

health#nvim#check
========================================================================
## Configuration
  - OK: no issues found

## Performance
  - OK: Build type: Release

## Remote Plugins
  - OK: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=^H
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~
  - INFO: $COLORTERM='rxvt'

health#provider#check
========================================================================
## Clipboard (optional)
  - OK: Clipboard tool found: xclip

## Python 2 provider (optional)
  - WARNING: No Python executable found that can `import neovim`. Using the first available executable for diagnostics.
  - ERROR: Python provider error:
    - ADVICE:
      - provider/pythonx: Could not load Python 2:
          /usr/bin/python2 does not have the "neovim" module. :help |provider-python|
          /usr/bin/python2.7 does not have the "neovim" module. :help |provider-python|
          python2.6 not found in search path or not executable.
          /usr/bin/python is Python 3.7 and cannot provide Python 2.
  - INFO: Executable: Not found

## Python 3 provider (optional)
  - WARNING: No Python executable found that can `import neovim`. Using the first available executable for diagnostics.
  - ERROR: Python provider error:
    - ADVICE:
      - provider/pythonx: Could not load Python 3:
          /usr/bin/python3 does not have the "neovim" module. :help |provider-python|
          /usr/bin/python3.7 does not have the "neovim" module. :help |provider-python|
          python3.6 not found in search path or not executable.
          python3.5 not found in search path or not executable.
          python3.4 not found in search path or not executable.
          python3.3 not found in search path or not executable.
          /usr/bin/python does not have the "neovim" module. :help |provider-python|
  - INFO: Executable: Not found

## Ruby provider (optional)
  - WARNING: `ruby` and `gem` must be in $PATH.
    - ADVICE:
      - Install Ruby and verify that `ruby` and `gem` commands work.

## Node.js provider (optional)
  - INFO: Node.js: v10.16.3
  - WARNING: Missing "neovim" npm (or yarn) package.
    - ADVICE:
      - Run in shell: npm install -g neovim
      - Run in shell (if you use yarn): yarn global add neovim

[tapyu]

I just have found the problem, actually the command should be

use {'iamcco/markdown-preview.nvim', run = 'cd app && yarn install'}

Even though, I couldn’t understand what was the problem in loading the plugin only when I call :MarkdownPreview…

[dimaportenko]

I just have found the problem, actually the command should be

use {'iamcco/markdown-preview.nvim', run = 'cd app && yarn install'}

Even though, I couldn’t understand what was the problem in loading the plugin only when I call :MarkdownPreview…

works for me, thanks!