The cause:

After I examined your progarm for a while, I found that there were 2 problem:

1, After you installed brew in macOS it was saved at the location – /opt/homebrew.

2, You did not set the path for brew installation.

Therefore, your error happend.

Solution:

To solve this error, first the brew command that you need have to be runned to the location of cd, then  go into the bin folder and run the brew commands again.

Another solution is adding the path of brew installation in the .zshrc file by these steps:

1, Use the command: nano ~/.zshrc to open the .zshrc file.

2, Add:  export PATH="$PATH:/opt/homebrew/bin/" to the file.

3, Use Enter press Control + X to save the file.

4, Use command: source ~/.zshrc to apply changes.

export Path=''$PATH:/opt/homebrew/bin/''

code2care@mac ∼ % brew
Example usage:
brew search TEXT|/REGEX/
brew info [FORMULA|CASK...]
brew install FORMULA|CASK...
brew update
brew upgrade [FORMULA|CASK...]
brew uninstall FORMULA|CASK...
brew list [FORMULA|CASK...]

Troubleshooting:
brew config
brew doctor
brew install --verbose --debug FORMULA|CASK

Contributing:
brew create URL [--no-fetch]
brew edit [FORMULA|CASK...]

Further help:
brew commands
brew help [COMMAND]
man brew
https://docs.brew.sh
code2care@mac ∼ %

Now the brew command can be runned from anywhere.