is there any way to do this?
Using lowercase characters for URLS is standard practice on the web. It isn’t impossible to use capital letters in a URL. I just think Wordpress is going to convert capitals to lower case when making the URL slug. See these for more info:
My personal opinion is that it is best to leave everything lower case. Your URL is in lowercase. Why not leave it all that way? You aren’t adding anything to the user experience by using capital letters in your URL slug anyway.