Simple node api reference URL: https://www.linkedin.com/learning-login/share?account=93557497&forceAccount=false&redirect=https%3A%2F%2Fwww.linkedin.com%2Flearning%2Freact-creating-and-hosting-a-full-stack-site-15153869%3Ftrk%3Dshare_ent_url%26shareId%3DrkRwIuTGRXaodImmEGtt7A%253D%253D express server database : MongoDB Firebase authentication