When I select the cell, open the tooltip on the selected cell. and content in a show like Formula, Some Text, etc. And using Microsoft Excel Add-in.
Search on Microshttps://www.microsoft.com/en-in/oft R&D on this problem
The Office JavaScript API (OfficeJS) doesn't provide anything for displaying a tooltip in Excel. But you can add comments to the Excel workbook. The Work with comments using the Excel JavaScript API article describes how to add, read, modify, and remove comments in a workbook with the Excel JavaScript API. You can learn more about the comment feature from the Insert comments and notes in Excel article.
You can post or vote for an existing feature request on Tech Community where they are considered when the Office dev team goes through the planning process.