How do I let down a guy who really likes me?

I’ve been speaking to someone for less than a week now.

We spoke on the phone for the first time and I didn’t like him.

I could tell he was really feeling me though.

How do I go about things now in the best way? 😭

Updates
1 y
Update: I let him know but he’s being persistent and he keeps texting me. I don’t want to be mean and block him.
How do I let down a guy who really likes me?
Post Opinion