Install Fastlane

On Mac

brew install fastlane

On Ubuntu

You need to install the build tools needed:

sudo apt-get update
sudo apt-get install build-essential

sudo gem install fastlane -NV

If you have an error during installation, try the following

/var/lib/gems/2.4.0/gems/unf_ext-0.0.7.7/unf_ext.gemspec
Building native extensions.  This could take a while...
current directory: /var/lib/gems/2.4.0/gems/unf_ext-0.0.7.7/ext/unf_ext
/usr/bin/ruby2.4 -r ./siteconf20200819-21694-1i2uh4u.rb extconf.rb
checking for -lstdc++... yes
creating Makefile
current directory: /var/lib/gems/2.4.0/gems/unf_ext-0.0.7.7/ext/unf_ext
make "DESTDIR=" clean
sh: 1: make: not found
current directory: /var/lib/gems/2.4.0/gems/unf_ext-0.0.7.7/ext/unf_ext
make "DESTDIR="
sh: 1: make: not found
ERROR:  Error installing fastlane:
	ERROR: Failed to build gem native extension.

    Building has failed. See above output for more information on the failure.
Building has failed. See above output for more information on the failure.
make failed, exit code 127

Gem files will remain installed in /var/lib/gems/2.4.0/gems/unf_ext-0.0.7.7 for inspection.
Results logged to /var/lib/gems/2.4.0/extensions/x86_64-linux/2.4.0/unf_ext-0.0.7.7/gem_make.out

https://dev.to/subbramanil/fastlane-setup-in-ubuntu-2dfb

https://stackoverflow.com/a/54425613

 358  sudo gem install fastlane -NV
  359  fastlane --v
  360  sudo gem install fastlane -NV
  361  sudo apt-get install ruby
  362  sudo gem install fastlane -NV
  363  sudo apt-get install rubygems ruby-dev
  364  sudo gem install fastlane -NV
  365  sudo apt install ruby ruby-dev
  366  export LC_ALL=en_US.UTF-8
  367  export LANG=en_US.UTF-8
  368  source ~/.profile
  369  sudo gem install fastlane
  370  sudo apt-get install libc6-dev
  371  sudo apt-get install g++
  372  sudo gem install fastlane
  373  sudo gem install fastlane -NV
  374  sudo apt-add-repository ppa:brightbox/ruby-ng
  375  sudo apt-get update
  376  sudo apt-get install ruby2.4
  377  ruby -v 
  378  sudo apt-get install ruby2.4-dev
  379  sudo gem install fastlane -NV
  380  fastlane -v
  381  sudo gem install fastlane
  382  ruby -v 
  383  gem install google-api-client -v 0.29.1
  384  sudo gem install google-api-client -v 0.29.1
  385  sudo apt-get install ruby-full
  386  sudo gem install fastlane -NV
  387  sudo apt-get install build-essential
  388  sudo gem install fastlane -NV
  389  fastlane -v

success