Help Create EndOfMonthDate using the Date Column in my Dataset

Hi All, 

I'm working with the dataset below, which contains a StartDate column. The source file's StartDate column was initially formatted as Jan 2024, Feb 2024. However, when extracted into Power Bi, I modified the date format by highlighting the "StartDate" column and then selecting "Data Type Text" under the Transform ribbon, followed by date, to convert the Startdate format.

I would want to use the StarDate field to add an EndOfMonth column.

Thank You!