In most cases, PTR records can only be set by your ISP. What you’d usually need to do is either give them a call and have them set it, or many ISP’s provide a web interface that allows you to set that.
There’s a handful of cases where ISP’s might delegate that to you in order to allow you to set that, but that’s fairly rare. I suspect the solution in your case would be to contact your provider and work with them to get your PTR records all setup.