Step-by-step – GnuCash Installation in Linux Mint 20

Installing

2. 2. Setting Up Flatpak

   How to Install Flatpak on Mint 20

   Flatpak Mint 20 Installation Guide

   Flatpak Mint 20 Setup

   First, check if it’s already there:

   which flatpak

3. 3. Installing GnuCash Flatpak

   Then to Install GnuCash Flatpak App on Mint 20
   Simply play:

   flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

   For further Insight see the Flatpak Official Documentation.
   And after:

   flatpak install https://dl.flathub.org/repo/appstream/org.gnucash.GnuCash.flatpakref

   The Flatpak App Setup do Not need the sudo Command because then it Runs confined into a Sandbox.
   However you’ll be Prompted to Authenticate with your User or Admin Pass.
   Then Confirm the proposed Setup with ‘Enter’ and wait until the App is Downloaded and Installed.