How to set hreflang links

Hi Folks,

We have a MU subdirectory network:

• http://www.example.com – Global/USA site
• http://www.example.com/uk/ – United Kingdom site
• http://www.example.com/au/ – Australian site

From this article, we need to set hreflang links for each page on our website.

For example, on http://www.example.com, we would need to have:

<link rel=“alternate” hreflang=“en-gb” href=“https://www.example.com/uk/” />

& something equivalent for Australia.

What would be the best way to achieve this?

Would using WPML be the solution?

Thanks.