Selenium - Uploading multiple files leads to uploading duplicate file (first file again and again)

I am using sendkeys in selenium (with blueprism) to automate uploading of multiple files.

I am using "C:\Selenium\TestData\Flexy - BigFile1.txt"+"\n"+"C:\Selenium\TestData\Flexy - BigFile2.txt" as send keys with different file path but it just leads to uplaoding same file again and again as BigFile1.txt , BigFile1 - 1.txt.

Please help