RawBT requires PHP 5.4.0+ to run.
The utility is distributed as a Phar package.

• Install PHP (if not installed yet)
• Download last release from https://github.com/402d/rawbt_ws_server/releases
• Unpack
• Copy files from dist folder
• Rename one from examples config
• Edit connect params

• Run server (rawbt.bat - The application starts in a minimized window)

• php rawbt.phar

• copy rawbt.service to /etc/systemd/system/rawbt.service
• edit User, Group (don't run it as root), WorkingDirectory and ExecStart
• sudo systemctl daemon-reload
• sudo systemctl enable rawbt.service
• sudo systemctl start rawbt.service

• Add bat file to startup

In the /doc directory you can find a useful utility (TrayIt) that can hide the window of a running server.

https://rawbt.ru/mike42/example_rawbt/

function pc_print(data){
    var socket = new WebSocket("ws://127.0.0.1:40213/");
    socket.bufferType = "arraybuffer";
    socket.onerror = function(error) {
	  alert("Error");
    };			
	socket.onopen = function() {
		socket.send(data);
		socket.close(1000, "Work complete");
	};
}		
function android_print(data){
    window.location.href = data;  
}
function ajax_print(url, btn) {
    $.get(url, function (data) {
		var ua = navigator.userAgent.toLowerCase();
		var isAndroid = ua.indexOf("android") > -1; 
		if(isAndroid) {
		    android_print(data);
		}else{
		    pc_print(data);
		}
    });
}

https://github.com/mike42/escpos-php/blob/development/example/rawbt-receipt.php

It is enough to specify the desired connector

    $connector = new RawbtPrintConnector();