Git clone and submodule command not working

hi, currently i am at step 9 Install Free5GC
not able to follow the step where git clone command is used.
Can please help me here that how it is getting linked with Git and ahow submodules were created.

Hi, maybe you can follow the command below.

$ git clone
$ cd free5gc
free5gc$ git submodule sync
free5gc$ git submodule update --init