encountered a problem as below, must I use &'static self or self instead of &self? Is there any other solution? Appreciate for any help

struct AuthToken {
    token: String,
    expires_at: i64,
}

pub(crate) struct Notifier {
    credential: Credential,
    auth_token: Arc<RwLock<AuthToken>>,
    http_client: reqwest::Client,
}