So ...

We are going to use a plugin called Revive Old Posts – Auto Post to Social Media.

Here it is:

https://wordpress.org/plugins/tweet-old-post/

It's a quite big plugin (2.80 MB), so let's start with the usual speed tests ...

Here are my results before installing the plugin ...

... and the result after installing and activating the plugin:

As you can see, it's a big plugin, but is definitely a well-coded one ...

So, let's see how it works ...