Reach out to your network or email your friends to put you in contact with potential users. It should be moderately easy since you're just asking for a free Skype call, you're not asking for money yet.
If you're having problem finding people to get on a free Skype call then it's a big red flag. You'll need to reconsider your positioning or your market. Because eventually you'll (presumably) be asking for money and that's even harder.
If you're having problem finding people to get on a free Skype call then it's a big red flag. You'll need to reconsider your positioning or your market. Because eventually you'll (presumably) be asking for money and that's even harder.