We have an asp.net application integrated with Online SharePoint (displaying a search results using legacy authentication). We are planning to block the legacy authentication in our online SharePoint tenant. I tried the SharePoint add-in but search (KQL) method getting error and one of the blog mentioned, Client ID need to create , provide tenant level permission. Instead of giving tenant level permission , please let me know if anyone implement this kind of solution.
Display search result in .net web application from online sharepoint using modern authentication.