All error codes

ip_not_found

HTTP 404 IP address not found

What happened

The public IP address id is not one this project can use for this operation. Reading or releasing an address answers this when the id was never ordered here, was already released, or belongs to another project; changing a router external address also answers it when the address is yours but is still attached to a server; attaching an address to a network card answers it when the id is not among the addresses GET /v1/ips lists for the project.

What to do

List the project's addresses with GET /v1/ips and use an id from there. If the address exists but is attached to a server, releasing it answers 409 ip_in_use instead - detach it from the interface or delete the server first.

Retrying

Repeating this request will not help.

How it arrives

{
    "type": "https://docs.fiberax.com/errors/ip_not_found",
    "title": "IP address not found",
    "status": 404,
    "code": "ip_not_found",
    "request_id": "a277dcd1ca652c65"
}

Branch your code on code, never on the wording of title.