Error trying to add private lists to sitelist

I have a private list and i can't add on sitelist the .txt files but the .xslx works. 

Any tips ? Thank you

of course you can not directly add a text file to verified urls as each of the urls has to be identified first on what engine it is.

You can tell me how i can do that ?

options->advanced->tools->Import URLs (identify platform and sort in)