LOWER DAX Function
The LOWER function converts all letters in a text string to lowercase.
DAX Syntax LOWER(text)
The function parameter text specifies the text we want to convert to lowercase, or a reference to a column that contains text.
Example: The following formula gets each row in the column, [Country], and converts the value to all lowercase. Numbers in the column are not affected.
DAX
Lowercase name = LOWER(Sheet1[Country])