This happened to me today. I found old project code without an SQL dump and just wanted to check if the project was still usable. Following are two ways you can recover the database schema from an FRM file.
Using the mysqlfrm utility by Oracle
This is a pretty handy command-line utility from the MySQL team. Check out the official documentation.
Online version of mysqlfrm
This is not the official one, but the TwinDB team created a Database Recovery portal to generate schema from .ibd and .frm files. It must be using the mysqlfrm utility behind the UI.
This log is for future reference. If you have any other tools, please mention them in the comments.