When i try:

gem install fastlane:2.206.2 -V

my output its:

ERROR: While executing gem … (Gem::FilePermissionError) You don’t have write permissions for the /usr/local/lib/ruby/gems/3.1.0 directory.

my env:

$ RubyGems Environment:
  - RUBYGEMS VERSION: 3.3.7
  - RUBY VERSION: 3.1.2 (2022-04-12 patchlevel 20) [x86_64-linux]
  - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/3.1.0
  - USER INSTALLATION DIRECTORY: /home/user/.local/share/gem/ruby/3.1.0
  - RUBY EXECUTABLE: /usr/local/bin/ruby
  - GIT EXECUTABLE: /usr/bin/git
  - EXECUTABLE DIRECTORY: /usr/local/bin
  - SPEC CACHE DIRECTORY: /home/user/.local/share/gem/specs
  - SYSTEM CONFIGURATION DIRECTORY: /usr/local/etc
  - RUBYGEMS PLATFORMS:
     - ruby
     - x86_64-linux
  - GEM PATHS:
     - /usr/local/lib/ruby/gems/3.1.0
     - /usr/local/share/gems/
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :backtrace => false
     - :bulk_threshold => 1000
     - :sources => ["https://my_repo.com/repository/rubygems/"]
     - :concurrent_downloads => 8
  - REMOTE SOURCES:
     - https://my_repo.com/repository/rubygems/
  - SHELL PATH:
     - PATH=PATH=PATH=/home/user/.local/bin
     - /home/user/bin
     - PATH=PATH=PATH=/home/user/.local/bin
     - /home/user/bin
     - /usr/local/bin
     - /usr/bin
     - /usr/local/sbin
     - /usr/sbin
     - /usr/bin/sonar-scanner/sonar-scanner/bin
     - /opt/tools
     - /opt/gradle/bin
     - /home/user/.rvm/bin
     - /usr/bin/sonar-scanner/sonar-scanner/bin
     - /opt/tools
     - /opt/gradle/bin
     - /home/user/.rvm/bin

i installed ruby through compiling the source code with:

$ ./configure
$ make
$ sudo make install

rvm is useless for me because im on intranet and cant download a tarball or whathever from internet.

Anyone figure out what can i do to solve this?
Thanks in advance.