How to change allowed characters for address of the site?

Hi!

I’m running multisite with subfolders, but I’m not really happy with how the address are defined for new page. I would like to be it https://www.mywebsite.com/my-very-own-blog rather than https://www.mywebsite.com/myveryownblog (so that while registering the site, the space between the words are turned into dashes). I guess it is defined in .htaccess, but how?