:echo has("python3") returns "0" even though i have pynvim installed

[Rentfunk]

I have installed pynvim as per instructions at https://github.com/Shougo/deoplete.nvim but it's not working in my vim. And i tried everything. Installing neovim. Then uninstalling both and installing only pynvim, but nothing happens. Can you help me with this?

[Shougo]

Please upload :checkhealth result.

[Rentfunk]

Well, :checkhealth command is not working in my vim. And this is what my pip3 freeze returns:

asgiref==3.2.5 
certifi==2019.11.28
Django==3.0.4
django-filter==2.2.0
greenlet==0.4.16
msgpack==1.0.0
neovim==0.3.1
pynvim==0.4.1
python-decouple==3.3
pytz==2019.3
sqlparse==0.3.1

And both neovim and pynvim are working in python3 shell:

Python 3.8.1 (v3.8.1:1b293b6006, Dec 18 2019, 14:08:53) 
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import neovim
>>> import pynvim

And here is my .vimrc file if it is of eny help:

filetype plugin indent on
syntax on
set tabstop=4
set shiftwidth=4
set expandtab

call plug#begin('~/.vim/plugged')

Plug 'jiangmiao/auto-pairs'

Plug 'dense-analysis/ale'

if has('nvim')
    Plug 'Shougo/deoplete.nvim', { 'do': ':UpdateRemotePlugins'  }
else
    Plug 'Shougo/deoplete.nvim'
    Plug 'roxma/nvim-yarp'
    Plug 'roxma/vim-hug-neovim-rpc'
endif

let g:deoplete#enable_at_startup = 1

let g:python3_host_prog = '/System/Library/Frameworks/Python.framework/Versions/Current/Resources/Python.app/Contents/MacOS/Python'

let g:ale_linters = {"javascript": ["eslint"]}
let g:ale_fixers = {"javascript": ["eslint"]}

let g:ale_fix_on_save = 1

call plug#end()

And here are the errors that i get, when i open vim:

[vim-hug-neovim-rpc] Vim(pythonx):Traceback (most recent call last):
Error detected while processing function deoplete#enable[9]..deoplete#initialize[1]..deoplete#init#_initialize[10]..<SNR>50_init_internal_variables[28]..neovim_rpc#serveraddr:
line   18:
E605: Exception not caught: [vim-hug-neovim-rpc] requires one of `:pythonx import [pynvim|neovim]` command to work

I found out, that i need to write that command :pythonx import [pynvim|neovim] but it's not working