In a module, how do I send values to a Theme file to be rendered?

I’m working on someones existing module and I’ve made a function that returns an array of data. I’d like that data to be sent to the .tpl file so it can be rendered on the front end.

How exactly do I do this?

I have a `hook_theme()` set up, but then what? How do I get the data from my array, to the hook_theme to be used on the .tpl file?

Any help is appreciated.

Many thanks in advance.

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