Select the folder and right click on the folder and select the AxCrypt | Encrypt menu option from the windows explorer context menu or
Right click on the Secured Folders area and choosing Add Secured Folder option from the context menu. or
You can able to encrypt your folder contents by just drag and drop the folder to the Secured Folders area.
Please check out our video tutorials at https://www.youtube.com/channel/UCoSoXBjq6iCG5232fHoWStA and our other documentation at https://www.axcrypt.net/information/get-started/ to get started with AxCrypt.
If the above does not help,please provide more information about the issue and write a mail to firstname.lastname@example.org . you can send a screenshot showing where the problem is, it often helps us understand.