Install QGis on Ubuntu

QGis.md

https://qgis.org/en/site/forusers/alldownloads.html#id16

sudo nano /etc/apt/sources.list

2. Copy and paste both lines

Change bionic by xenial depending the version of your ubuntu

For Ubuntu 16.04 use xenial

For Ubuntu 18.04 use bionic

For Ubuntu 19.04 use disco

deb     https://qgis.org/debian bionic main
deb-src https://qgis.org/debian bionic main

afeter

ctrl+o
ctrl+x

wget -O - https://qgis.org/downloads/qgis-2019.gpg.key | gpg --import
gpg --fingerprint 51F523511C7028C3

gpg --export --armor 51F523511C7028C3 | sudo apt-key add -

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key 51F523511C7028C3

sudo apt-get update

sudo apt-get install qgis qgis-plugin-grass

Doc Java https://gist.github.com/ridixcr/3311083d7b9003250c5a3d5bc941a044

Doc NodeJS https://gist.github.com/ridixcr/a3502cbcf2ad40ff69fad2a270c8c374

Doc QGis https://gist.github.com/ridixcr/3017e1fafe2324bbe4f0a67c3765efbf

Uninstall QGis https://www.howtoinstall.co/en/ubuntu/xenial/qgis?action=remove

I just tried this and got these errors:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help resolve the situation:

The following packages have unmet dependencies:
 python-qgis : Depends: python-qgis-common (= 1:3.4.4+28bionic) but it is not going to be installed
               Depends: libqgis-analysis3.4.4 but it is not going to be installed
 qgis : Depends: libqgis-analysis3.4.4 but it is not going to be installed
        Depends: libqgis-app3.4.4 but it is not going to be installed
 qgis-plugin-grass : Depends: libqgis-app3.4.4 but it is not going to be installed
                     Depends: grass-core but it is not going to be installed
                     Depends: grass740
E: Unable to correct problems, you have held broken packages. 

I updated the steps to install the Qgis in version 3.8.x Zanzibar