Cannot update remote plugins

When I try to run :UpdateRemotePlugins, I get this

Encountered AttributeError loading plugin at /Users/tsitnikov/.vim/plugged/neovim-ascii-diagram/rplugin/python3/ascii_diagram.py: module 'neovim' has no attribute 'api'
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/pynvim/plugin/host.py", line 171, in _load
    module = imp.load_module(name, file, pathname, descr)
  File "/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/lib/python3.8/imp.py", line 234, in load_module
    return load_source(name, filename, file)
  File "/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/lib/python3.8/imp.py", line 171, in load_source
    module = _load(spec)
  File "<frozen importlib._bootstrap>", line 702, in _load
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
AttributeError: module 'neovim' has no attribute 'api'
remote/host: python3 host registered plugins []
remote/host: generated rplugin manifest: /Users/tsitnikov/.local/share/nvim/rplugin.vim
Press ENTER or type command to continue

My OS is Mac OSX

Vim version:

:version
NVIM v0.4.3
Build type: Release
LuaJIT 2.0.5
Compilation: /usr/local/Homebrew/Library/Homebrew/shims/mac/super/clang -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -DNDEBUG -DMIN_LOG_LEVEL=3 -Wall -Wextra -pedantic -Wno-unused-paramet
er -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fdiagnostics-color=auto -DINCLUDE_GENERATED_DECL
ARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/tmp/neovim-20191107-13403-1or2rj3/neovim-0.4.3/build/config -I/tmp/neovim-20191107-13403-1or2rj3/neov
im-0.4.3/src -I/usr/local/include -I/tmp/neovim-20191107-13403-1or2rj3/neovim-0.4.3/deps-build/include -I/usr/local/opt/gettext/include -I/Applications/Xcode.app/Contents/Developer
/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/usr/include -I/tmp/neovim-20191107-13403-1or2rj3/neovim-0.4.3/build/src/nvim/auto -I/tmp/neovim-20191107-13403-1or2rj3/neo
vim-0.4.3/build/include
Compiled by brew@Mojave.local

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

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/local/Cellar/neovim/0.4.3/share/nvim"

My checkhealth show the following:

health#coc#check
========================================================================
  - OK: Environment check passed

  - OK: Javascript entry lib/attach.js found
  - OK: Service started

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

## Performance
  - OK: Build type: Release

## Remote Plugins
  - WARNING: "neovim-ascii-diagram" is not registered.
  - WARNING: Out of date
    - ADVICE:
      - Run `:UpdateRemotePlugins`

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

## tmux
  - OK: escape-time: 10ms
  - INFO: $TERM: xterm-256color
  - ERROR: $TERM should be "screen-256color" or "tmux-256color" in tmux. Colors might look wrong.
    - ADVICE:
      - Set default-terminal in ~/.tmux.conf:
          set-option -g default-terminal "screen-256color"
      - https://github.com/neovim/neovim/wiki/FAQ

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

## Python 2 provider (optional)
  - INFO: `g:python_host_prog` is not set.  Searching for python2 in the environment.
  - INFO: Executable: /usr/local/bin/python2
  - INFO: Python version: 2.7.17
  - INFO: pynvim version: 0.4.2
  - OK: Latest pynvim is installed.

## Python 3 provider (optional)
  - INFO: `g:python3_host_prog` is not set.  Searching for python3 in the environment.
  - INFO: Executable: /usr/local/bin/python3
  - INFO: Python version: 3.8.5
  - INFO: pynvim version: 0.4.2
  - OK: Latest pynvim is installed.

## Ruby provider (optional)
  - INFO: Ruby: ruby 2.7.0p0 (2019-12-25 revision 647ee6f091) [x86_64-darwin18]
  - INFO: Host: /Users/tsitnikov/.rvm/gems/ruby-2.7.0/bin/neovim-ruby-host
  - OK: Latest "neovim" gem is installed: 0.8.1

## Node.js provider (optional)
  - INFO: Node.js: v14.4.0
  - INFO: Neovim node.js host: /usr/local/lib/node_modules/neovim/bin/cli.js
  - OK: Latest "neovim" npm/yarn package is installed: 4.9.0

povilasb / neovim-ascii-diagram

Cannot update remote plugins #1