#Open terminal or ssh (by any ssh client like putty.exe) and write the following:

# Let you system package up to date

for Arabic life Preview

https://youtu.be/TZRe53l1lw4

sudo apt-get update -y

#install Postgresql database

apt-get install postgresql -y

# Install pip and pip3 command

sudo apt install python3-pip -y

sudo apt install python-pip -y

#As per your processor technology chose the correct acrobat reader(pdf) from the following versions

# note that :- you must go to the odoo installation URL to check the current suitable version for wkhtmltopdf because in the last year
odoo was depend on wkhtmltopdf release 12.1 but now odoo use release  wkhtmltopdf 12.5
#for ubuntu16

cd /tmp

wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.5/wkhtmltox_0.12.5-1.xenial_i386.deb

sudo dpkg -i wkhtmltox_0.12.5-1.xenial_i386.deb

apt-get -f install

#for ubuntu 18 or 20   processor type  generic AMD

cd /tmp

wget https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox_0.12.6-1.bionic_amd64.deb
dpkg -i  wkhtmltox_0.12.6-1.bionic_amd64.deb

apt-get -f install -y

cd

#for ubuntu 18. or 20   processor type  generic i386

cd /tmp

wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.5/wkhtmltox_0.12.5-1.bionic_i386.deb

sudo dpkg -i wkhtmltox_0.12.5-1.bionic_i386.deb

apt-get -f install -y

cd /

#for ubuntu   18 or 20   processor type  xenial AMD

cd /tmp

wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.5/wkhtmltox_0.12.5-1.xenial_amd64.deb

sudo dpkg -i wkhtmltox_0.12.5-1.xenial_amd64.deb
apt-get -f install -y

cd /

#for ubuntu 18. or 20   processor type  xenial i386

cd /tmp

wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.5/wkhtmltox_0.12.5-1.xenial_i386.deb

sudo dpkg -i wkhtmltox_0.12.5-1.xenial_i386.deb

apt-get -f install -y

cd /

#Add odoo community key (its valid to  all odoo different versions)

wget -O - https://nightly.odoo.com/odoo.key | apt-key add -

#Chose on of the following odoo version (only one) and copy line to your terminal (or ssh)

                         For #odoo10

echo "deb http://nightly.odoo.com/10.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

                         For #odoo11

echo "deb http://nightly.odoo.com/11.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

                         For #odoo12

echo "deb http://nightly.odoo.com/12.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

                         For #odoo13

echo "deb http://nightly.odoo.com/13.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

                         for #odoo14

echo "deb http://nightly.odoo.com/14.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

                         for #odoo15

echo "deb http://nightly.odoo.com/15.0/nightly/deb/ ./" >> /etc/apt/sources.list.d/odoo.list

#Install odoo by the following command line

apt-get update && apt-get install odoo

# If you face any error that mean you need to install first some package required 

apt-get -f install

 #install python to enable pip and pip3 commands

sudo apt install python3-pip -y

sudo apt install python-pip -y

 #python module is needed to export into xls format to export  or import excel file from Odoo
for odoo 10

sudo pip install xlwt
other odoo>odoo10

sudo pip3 install xlwt

# For converting amounts to words (in sales order or invoices and so on...)

for odoo 10

sudo pip install num2words

sudo pip3 install num2words

# For Right To left web====  if you face any issus with right to left ony

       #1- remove any old not combatable nodjs and npm

rm -r /usr/lib/node_modules

sudo apt remove nodejs -y

sudo apt purge nodejs -y

sudo apt-get remove --purge nodejs

sudo apt-get --purge remove nodejs node npm

sudo apt-get clean

sudo apt-get autoclean

sudo apt-get -f install

sudo apt autoremove -y

           # 2-Install apt package 'nodejs' and 'npm' temporary.

sudo apt install -y nodejs npm

         #3- Install npm package 'n' for managing Node.js versions.

sudo npm cache clean

sudo npm install n -g

         #4- Install latest stable Node.js.

sudo n stable

       #5-to correct node parth

sudo ln -sf /usr/local/bin/node /usr/bin/node

npm install -g rtlcss