async send(slackData, url) {
        if ((!url || typeof url !== 'string') || !validator.isURL(url)) {
            const err = new errors.InternalServerError({
                message: 'URL empty or invalid.',
                code: 'URL_MISSING_INVALID',
                context: url
            });

            return this.#logging.error(err);
        }

        const requestOptions = {
            body: JSON.stringify(slackData),
            headers: {
                'user-agent': 'Ghost/' + ghostVersion.original + ' (https://github.com/TryGhost/Ghost)'
            }
        };

        if (process.env.NODE_ENV?.startsWith('test')) {
            requestOptions.retry = 0;
        }

        return await got.post(url, requestOptions);
    }
@param {object} slackData
@param {URL} url

@returns {Promise<any>}