Error handling in Craft
The usual method for debugging a Craft site is to pull down a copy of the production database content, import it into your local development database and run a local copy of the site's code on your computer. You can run the site using Craft's Nitro development environment, or use other local development environment frameworks like Valet or MAMP.
Once you have this local development site running, you can make changes to the templates to help debug issues or view the properties of objects, just by modifying the Twig templates. The Twig dump function is useful for viewing the contents of an object to see which properties you have available:
{% for tweet in craft.ssTwitterFeed.displayPost( '4' ) %}
    {{ dump(tweet) }}
{% endfor %}

If you're running the site with devMode enabled, the dd tag (Dump-and-die) is also helpful. This will dump out the variable and nothing else, i.e. your page won't render but instead you will get a formatted dump of the variable you're inspecting:
{% dd(craft.ssTwitterFeed.displayPost('4')) %}