Access to the Web API without static IP whitelisting

We are running into an issue with accessing the web API from a hosting provider that does not have a static IP address. Our outbound IP addresses are dynamic and they can and will change often due to the hosting provider's cloud-based container infrastructure.

Is it possible to allow access to the API from particular subdomains (example: dev.mysite.com) instead of IP address, or get access in some other way? If not, how can we work around this issue? Thanks in advance.