Lertap 5 is an Excel application. Your computer must be able to run Excel, the spreadsheet program from Microsoft, usually distributed as one of the applications in the software suite called "Microsoft Office". Other applications in this suite are Word, Access, and PowerPoint.
So? Excel. You need it to run Lertap 5. Got it? Good. But note: your copy of Excel has got to be one which will "run macros". The version of Excel for the iPad is not capable of running macros. The various "mobile" versions of Excel, handy and powerful as they may be, are not capable of running macros either. (Macros are modules of computer code; Lertap 5 code is written in "VBA", Visual Basic for Applications.)
Do you have a Windows computer using Excel 2007, Excel 2010, Excel 2013, or Excel 2016, or a Macintosh using Excel 2016? If not, you're reading the wrong document (sorry). This here document is meant to be used as a helpful companion, a warm hand holder, as you run the Excel 2007/2010/2013/2016 versions of Lertap.
Excel 365 is a version name used by Microsoft when a user has taken out an annual subscription to Office 365. As of April 2018, it referred to Excel 2016.