Hello, my website is built in Traditional Chinese, which does not support the predictive search function. I tried to find the solution in this platform, but I cannot find the same file as I am using the theme Upire 12.0.
How can I make it work?
Hi @AidaptHK 
fully implementing predictive search is waaay beyond the scope of the forums.
For any type of technical thing you need to ask specific scoped questions showing your work then hope for free contributions or just hire someone.
To DIY the development work by yourself start here https://shopify.dev/docs/storefronts/themes/navigation-search/search/predictive-search
There are also plenty of paid search apps on the app store.
As for skus based search that’s a further complicataion.
If you need this customization actually implemented as then contact me for services.
Contact info in forum signature below 
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ALWAYS please provide context, examples: store url, theme name, post url(s) , or any further detail in ALL correspondence.
Hi @AidaptHK
If you are open to a 3rd party app, this app allows you to search by product title, description, sku, barcode, option, metafield, collection and pages: https://apps.shopify.com/ultimate-search-and-filter-1
Hi @AidaptHK ,
Please send the website link, I will check it for you
I have posted a solution for new dawn theme (15.4.0) here - SKU to Predictive Search - Dawn theme - 2023 - #3 by lixonic