Problem with open app Skype, iMessage, WhatsApp after click url on website?

I am beginner web developer. I have website. I have url:

- Skype - <a href ="skype:600000000">Skype me</a>
- Call - <a href ="tel:600000000">Call me by phone</a>
- iMessage - <a href ="tel:600000000">Send me message by iMessage</a>
- Whatsapp - <a href ="whatsapp://name">Send me message by Whatsapp </a>

I need after clicking Skype - call the selected number from the Skype application. After clicking WhatsApp / iMessage - open and write a message to the selected number from WhatsApp / iMessage.

How to do it At the moment applications are opening, but they are not dialing the right number

How can I repair it?

via Chebli Mohamed