Function import_key_jwk 

pub async fn import_key_jwk(
    variant: Sha2Variant,
    jwk: impl Into<String>,
    options: MacKeyOptions,
) -> Result<Mac, Error>

Import an RFC 7517 oct JSON Web Key (as JSON text) as an HMAC key over variant. See the WIT mac-key.export-key-jwk doc for the package-wide JWK contract.