"Unable to recognize" yarn "item as cmdlet, function, script file

   Initially, it should be you yarn Not installed , Or you installed , But the environment variable is not configured , The system cannot find the command .

1、 Check yarn Environment variables of

2、yarn Download address

Download and install , Generally, the environment variables can be automatically configured , If you don't have it, just manually configure it . 

https://repo.huaweicloud.com/yarn/v1.22.4/yarn-1.22.4.msihttps://repo.huaweicloud.com/yarn/v1.22.4/yarn-1.22.4.msi

3、 Check yarn Is the installation successful

See that the installation is successful