PHP shell_exec – some shell commands not available

before starting – I have seen some SO similar questions, but tbh I got even more lost.

I am trying to run nvm use and nvm -v within the PHP shell_execute, but am constantly getting the following error:

sh: nvm: command not found

It seems like PHP is using Bourne shell where nvm is not available.
I am mostly using Bash in Terminal where everything is fine (in other shells like ZSH I get the same error).

Questions:

How can I make PHP run commands with shell_exec (if there is alternative I am open for considering it) I usually use in Bash?

Extra notes (maybe helpful):

1. This command is only used on a local environment so changing settings on dev machine is something I am open to consider. (would be good to support Mac/Win and Linux, but Mac is the main focus at the moment).

2. If I run which nvm in the bash I get nothing in the terminal.

3. NVM was installed with Brew (don’t know if that has any impact)

The usecase:

I am building a WP CLI toolkit where one of the commands is wp custom install. The command should switch to the right Node.js version of the project, install npm and php dependencies as well as some extra things.

// basic code sample
namespace Custom/CustomCli;

class CustomCli {

    public static function init(){
    
        if( !(defined('WP_CLI') && WP_CLI) ) return;
        WP_CLI::add_command( 'custom', 'CustomCustomCli' );

    }
    
    /*
    * If the Node.js version !== to .nvmrc try 'nvm use'
    * after correct version is selected run 'npm install'
    * also run 'composer install' and 'composer dump-autoload'
    */
    public function install( $args ){
        WP_CLI::log( shell_exec('nvm -v') ); # once I figure out this I guess I'll know how to fully handle installation
    }

}

CustomCli::init();