sudo apt-get install ros-$ROSDISTRO-turtlebot3-bringup ros-$ROSDISTRO-turtlebot3-description ros-$ROSDISTRO-turtlebot3-gazebo ros-$ROSDISTRO-turtlebot3-msgs
roscd && cd src
ln -s <path-to-cloned-repo> .
cd ..
catkin build
roslaunch ttb_slam <file>.launch
roscd ttb_slam && cd test
python2 <test-file>.py
roscd ttb_slam && cd assets/aruco_marks
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:$PWD
You can also add the export to your .bashrc