Running commands like ar_send mail from a HTTP request

Hi I am new to rails so I apologize if this question seems silly.

I have set up ar_mailer in my app and its working great. the problem
is I will be running my app on a shared hosting plan where I don’t
have access to the command line.

The service says they can schedule tasks using HTTP request which
makes sense but how do I get the command “ar_sendmail” to run from a
controller. Normally I would just run that command or a derivative of
it from the root of my app.

Thanks in advance.