schedule/automated post to social media chennels

HI.

Does anyone been able to find addon that are also free or opensource that make it possible to schedule post to the different social medialike facebook, instagram, twitter etc. Would really appreciate if anyone now such system or can provide step by step guide to get it to work

HI.
Does anyone been able to find addon that are also free or opensource that make it possible to schedule post to the different social medialike facebook, instagram, twitter etc. Would really appreciate if anyone now such system or can provide step by step guide to get it to work