Missing export implementation (#330)

DaniDoro · web-flow · commit 83770070dad2 · 2021-07-22T17:11:03.000+02:00
Added missing export implementation for "Multiple ping pong nodes"
diff --git a/_docs/tutorials/core/first_application_linux/index.md b/_docs/tutorials/core/first_application_linux/index.md
@@ -102,6 +102,8 @@ cd microros_ws
 source /opt/ros/$ROS_DISTRO/setup.bash
 source install/local_setup.bash
 
+export RMW_IMPLEMENTATION=rmw_microxrcedds
+
 ros2 run micro_ros_demos_rclc ping_pong
 ```
 
