below as reference, part of the long list that i’ve used for successful production deployment on ubuntu 20.04
create a user and login
sudo adduser erp_administrator
sudo usermod -aG sudo erp_administrator
su - erp_administrator
create .cache folder to claim local .cache folder permission
mkdir .cache
export LC_ALL=C.UTF-8
install aptitude for package downgrade
sudo apt install aptitude
solve ldap lib dependency
pick n, Y and Y for libldap2 1.2 if prompted
sudo aptitude install libldap2-dev
solve launchpadlib dependency
sudo apt install python3-testresources
install production erp bench
wget https://raw.githubusercontent.com/frappe/bench/develop/install.py
sudo python3 install.py --production --verbose --user erp_administrator --frappe-branch version-12 --without-erpnext --mariadb-version 10.5 --bench-name erp_bench
cd erp_bench
solve erpnext numpy and pandas dependency
env/bin/pip install numpy==1.18.5
env/bin/pip install pandas==0.24.2
get erpnext
bench get-app --branch version-12 erpnext
bench --site site1.local install-app erpnext