Username & Password forNice Hash

I am trying to mine LTC through buying hash power on Nice Hash. I have tried to enter wallet address as the username for Nice Hash but I get the following when I try to verify the pool:

"Establishing connection with pool ###.###.###.###.... Error: null
Your pool is shown as incompatible therefore we encourage you to contact pool operator to make sure that the pool is using minimal/starting pool share difficulty which is compatible with our service (and thus compatible with today's miners), please send them following link: https://www.nicehash.com/help/which-mining-pools-are-supported. Thank you!"

Also it does not allow blank passwords.

Thanks