Argument from anecdote

An argument from anecdote is an informal logical fallacy, where anecdotal evidence is presented as an argument; without any other contributory evidence or reasoning. This type of argument is considered as an informal logically fallacy as it is unpersuasive – since the anecdote could be made up, misconstrued or be a statistical outlier which is insignificant when further evidence is considered. This fallacy can often be found in conjunction with the hasty generalisation fallacy – where the hasty generalisation is made from unsubstantiated anecdotes.

en.wikipedia.org/wiki/Argument_from_anecdote