Hi and welcome to the forum! This change can’t be done because this is a shared hosting server, so the reverse DNS can’t be one of your websites, and also because it’s not your server, if I understand what you mean; plus for me your website works fine and resolves to that IP anyway.
If it still doesn’t work on your side, please note that, if you created your website recently, it might take up to 72 hours for it to work on your side due to DNS caching: