@italbeauty Hi there,
For security reasons, a metafield can be changed from the third-party server, not from the theme code. If you want to handle with it, you must rent some server and create a simple private app.
Also, you can try to find some metafield app, that has such feature as a changing metafield from the Order page.
Thank you so much Sasha!
Do you have some pointers on how to build a small app to perform this action? I am not clear how I can connect from the order page to this small app to update the metafield.
I checked on the app store and I couldn't find any app that can performe the update from the order page, are you aware of any? thanks! I