SHELL

yarn: command not found

npm install --global yarn

command not found: yarn

# if yarn is installed, but not linked
brew link yarn

bash: yarn: command not found

Did you download and install Yarn in .msi format?
#https://classic.yarnpkg.com/latest.msi

I also downloaded and installed from the site, but git did not appear in GIT Bash.

I turned off Windows and turned it on again, everything worked