problem description

follow the regular react-native official steps to execute the command. At last, the run prompts you as shown in the figure, but he does not produce the simulator

the environmental background of the problems and what methods you have tried

related codes

/ / Please paste the code text below (do not replace the code with a picture)
the related code is
Signing for "hello" requires a development team.

what result do you expect? What is the error message actually seen?