The developer has indicated that the crate is unmaintained.
The last release is over three years old (from 2021), the crate depends on the deprecated async-std crate and on a very old version of rustls for TLS support.
async-std
rustls
{ "license": "CC0-1.0" }
{ "affected_functions": null, "affects": { "os": [], "functions": [], "arch": [] } }
{ "cvss": null, "informational": "unmaintained", "categories": [] }