On macOs I manage to fix this by adding:
export ANDROID_HOME=$HOME/Library/Android/sdk
export PATH=$PATH:$ANDROID_HOME/emulator
export PATH=$PATH:$ANDROID_HOME/tools
export PATH=$PATH:$ANDROID_HOME/tools/bin
export PATH=$PATH:$ANDROID_HOME/platform-tools
to ~/.zsh_profile file.
and than type to your terminal
source $HOME/.zsh_profile
The issue was caused by using iTerm2 shell so it's required to edit its own config instead of default $HOME/.bash_profile as described in the official documentation https://reactnative.dev/docs/environment-setup