I was trying to follow this ROS tutorial https://wiki.ros.org/tf/Tutorials/Introduction%20to%20tf

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But when I use the command roslaunch turtle_tf turtle_tf_demo.launch, I got the following two errors:

process[turtle1_tf_broadcaster-4]: started with pid [50342] /usr/bin/env: «python»: No existe el archivo o el directorio

and

[turtle1_tf_broadcaster-4] process has died [pid 50342, exit code 127, cmd /opt/ros/noetic/lib/turtle_tf/turtle_tf_broadcaster.py __name:=turtle1_tf_broadcaster __log:=/home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle1_tf_broadcaster-4.log]. log file: /home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle1_tf_broadcaster-4*.log [turtle2_tf_broadcaster-5] process has died [pid 50344, exit code 127, cmd /opt/ros/noetic/lib/turtle_tf/turtle_tf_broadcaster.py __name:=turtle2_tf_broadcaster __log:=/home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle2_tf_broadcaster-5.log]. log file: /home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle2_tf_broadcaster-5*.log [turtle_pointer-6] process has died [pid 50349, exit code 127, cmd /opt/ros/noetic/lib/turtle_tf/turtle_tf_listener.py __name:=turtle_pointer __log:=/home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle_pointer-6.log]. log file: /home/luisefa1998/.ros/log/bb3fdcf6-a4fd-11ec-bd5f-dfc11b444c15/turtle_pointer-6*.log

Does anyone know what the problem is? I tried to install the turtle_tf package but I can't, the terminal says that I already have it installed. Inside the package folder there are no python files that I need. The package folder is supposed to have these files but my directory doesn't have the node and src folders. Are there any extra plugins that I need to install for ROS Noetic?