I need to restrict specific users to read/update property bag values in SharePoint Online web part.
Only few users should have get/set permissions.
Any references or leads would be appreciated.
The only thing you can do is when you build your web part, you may give the second time verification. Like, set a whitelisted group inside of your code. There is calling APIs when you create a web part, so you can try to give the validate the user ID if he/she can access the web part.