ESP8266_RTOS_SDK installation failed

I have installed this SDK but when I try to get started with the first example ‘hello_word’ I run into problems. When I run ‘make menuconfig’, I get the message that the Python requirements are not satisfied, but on the other hand, when I run the suggested code: python3 -m pip install --user -r $IDF_PATH/requirements.txt
I get for all ‘Requirement already satisfied’
I also get the message in Dutch:
make: ***Er is geen regel om doel ‘check_python_dependencies’ te maken, nodig voor ‘menuconfig’. Gestopt. (=There is no rule to make the target ‘check_python_dependencies’, necessary for ‘menuconfig’. Stopped.).