How to download and setup pusher-http-php
Open terminal and run command
                                            git clone https://github.com/pusher/pusher-http-php.git
                                        
                                        git clone is used to create a copy or clone of pusher-http-php repositories.
                                        You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with pusher-http-php https://github.com/pusher/pusher-http-php/archive/master.zip
Or simply clone pusher-http-php with SSH
                                            [email protected]:pusher/pusher-http-php.git                                    
                                    If you have some problems with pusher-http-php
You may open issue on pusher-http-php support forum (system) here: https://github.com/pusher/pusher-http-php/issuesSimilar to pusher-http-php repositories
Here you may see pusher-http-php alternatives and analogs
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