-x selects a proxy. -X sets an HTTP request method. If a command says curl -x DELETE ..., curl reads DELETE as the proxy endpoint and may try to resolve it as a hostname.

Correct the option before changing DNS, adding a bypass rule, or replacing proxy credentials. The error names the argument curl parsed; it does not establish that a real proxy server called DELETE exists.

curl --request DELETE --url https://example.com/resource

This is an illustrative method and destination. A request can still inherit a proxy from other configuration. If an explicit proxy is intended, add its separate --proxy option with the actual endpoint. An address from the free proxy list is a public candidate for that option when the request is allowed through a public intermediary; retain its supported protocol in the value.

For long commands, the full option names make this distinction easier to review. The same spelling mistake can surface with POST or PUT, and an omitted option argument can also shift how the following text is interpreted.

Erthyglow kevrennek