Multi Language localization re SEO for Greater China (3 types of Chinese)

Question:
Using embedding custom code in Wix, is there a way I can alter the hreflang tags?

Product:
Wix Editor

What are you trying to achieve:
I created a multilingual website for English and Greater China (Hong Kong, Taiwan, China). In the Wix multilingual module, I can only select one Chinese, which I have selected for Hong Kong. I have added also Twi (TW) for Taiwan and Sardinian (SC) for China. From the user perspective the website is usable for Greater China, with 3 types of Chinese.

From an SEO perspective, is my main question.
On webpage’s header, Wix auto generated hreflang as follow:

<link rel="alternate" href="https://www.lazywealthy.com/" hreflang="x-default"/>
<link rel="alternate" href="https://www.lazywealthy.com/sc" hreflang="sc-it"/>
<link rel="alternate" href="https://www.lazywealthy.com/tw" hreflang="tw-gh"/>
<link rel="alternate" href="https://www.lazywealthy.com/zh" hreflang="zh-hk"/>
<link rel="alternate" href="https://www.lazywealthy.com/" hreflang="en-us"/>

Using custom code in Wix, is there a way I can alter the hreflang, so it becomes like this for Taiwan (zh-cn) and (zh-tw)?

<link rel="alternate" href="https://www.lazywealthy.com/sc" hreflang="zh-cn"/>
<link rel="alternate" href="https://www.lazywealthy.com/tw" hreflang="zh-tw"/>

Would be great if the search engines can read the website language correctly.

What have you already tried:
Tried these resources to no avail. I need to override the Wix default hreflang?
https://support.wix.com/en/article/header-code-meta-tag-guidelines
https://support.wix.com/en/article/embedding-custom-code-on-your-site

Wix actually have a very simple solution to customize the hreflang, as follow:

  1. Go to the Multilanguage module from “Manage Languages”.

Screenshot 2024-07-10 200036

  1. Click on the “… icon” and select “Set regional format” for the language you want to custom the hreflang tag.

  1. Select the Region locale you want (afterwards hit publish to be safe).

Screenshot 2024-07-10 200116

  1. Check the hreflang tag on the web page to see if you get the desired result.