Best way to know about authentic post?

An authentic post will give the company’s name and website, should you want to look into them before applying. They’ll offer a salary (hourly or yearly, depending on the work). They may also either have you apply via Indeed and require you to complete a skills test, or accessing their application will take you offsite to their company page. Just use good judgement. If someone seems too good to be true, it probably is. If their website is barely operational, while they still may be a legit company, you might want to rethink applying for them. It all common sense. Trust your gut. :)