How to install flarum on a shared hosting that doesn't have the composer function?
Easy!
Install composer in your local computer.
Create a new folder to save the flarum files.
Open a command prompt window.
Enter in the chose folder using the command prompt(cd folder_name).
Execute the following command:
composer create-project flarum/flarum . --stability=beta
Now, open the folder that you chose in file explorer.
Zip the folder and upload it to your shared hosting server.
Unzip the files in the www folder of your shared hosting.
Install Flarum & Be happy!
Sorry for my english, i'm not a native speaker.