You want your website to be accessible also for people outside your country, for example for Spanish speaking nations but you don’t want to translate all your pages manually? Then use Weglot, the translation tool that does the heavy-lifting for you.
You just install the Weglot in your Squarespace website:
Home menu -> Settings -> Language and region -> Site Languages -> Multilingual by Weglot -> Connect
After this you just have to create a Weglot account and choose a free or paid plan. The free plan includes 2000 words to be translated in 1 language.
Weglot is great because it actually uses a combined translator engine, composed by: Microsoft Translator, Google Translate and my favorite DeepL. From these 3, DeepL is the most accurate in translations but it does not support so many languages as Google Translate. The unsupported languages in Weglot are translated by Google Translate and finally the second fallback for DeepL is Microsoft Translator.

Human translation
If the developer would implement an automatic translation for a text, a translation API would just translate it in the foreign language and then the developer would display it on the website. Weglot offers a different approach !
You get the option to edit the translated text and correct it the way you think it’s more correctly translated. So besides the neural machine translation there is also the editor’s translation option where you, the editor can correct the automatic translation manually or visually.

Using the visual editor for correcting automatic translations is like a preview mode of your translated website page and you can go directly to a title or a paragraph, hover with the mouse over it and the pencil icon appears and clicking on that will make the text editable.
How about dynamic content, will they get a translation too?
Now this part is just amazing. Let’s say you have a fullcalendar implementation of a google calendar. The events are loaded through this plugin and displayed in a table that looks like a calendar. This table with the events is generated through javascript after all the Squarespace content has been loaded.
Yes, also dynamically created content can be translated, but this actually needs extra work. You need to tell specifically Weglot, what are the id or class attributes of these elements that were dynamically created.

Translating media
You can also add an alternative for your image by adding an alternative URL for your image for the other language:

You can find the link to this modal window on the bottom of the translations (in that specific language).

SEO benefits
Translated websites are served with a prefix in URL of that language shorthand. For example your website is called myawesomewebsite.com/about then the spanish version would be es.myawesomewebsite.com/about. Weglot also adds certain tags that communicate with search engines that this website has translated versions available.
Ex:
<link href="https://es.myawesomewebsite.com/about" hreflang="es" rel="alternate">
Translated pages are indexed in Google(can’t say the same with pages translated only with Google transpate API).
That’s about it, if you want to find out more, visit Weglot’s official website: https://weglot.com/