Options for static IP requirement while keeping my apps on App Platform?

I’m working on a project and for simplicity I’m using App Platform for my REST API application.

I am integrating with a 3rd party API that requires whitelisting a static IP address, which App Platform does not support.

My first thought to solve this issue was to setup a proxy on a droplet with a floating IP that forwards requests to my API URL but can serve as the static IP gateway for requests to/from this 3rd party.

Would something like this work or is there a simpler alternative I could consider?

I was hoping to avoid having to manage a droplet and was hoping for an out-of-the-box solution for something like this.