we are sending an sms to few internal stakeholders if a work order is raised. the request from the azure services to the sms service provider platform is through aparticular url. this url has to be whitelisted on the sms service provider platform in order to provide response. the sms provider doest want to whitelist the url and instead asking for ip addresses. but we are coming to know that the ip address from where the request comes will be changin on a periodic basis. so its kind of a dead end of the road and we werent able to do anything. the only solution was to put a VM and host the api in vm and the request is sent from the vm to the sms service provider platform. the ip address from VM would be static. this VM is an additional cost to us which can be prevented. we need a solution for this without the VM.