When the message option will be enable?

Answer 1

You can send the message to after 21 days when you join the sololearn and don't attach irrelevant tags

Answer 2

As @Sakshi mentioned, you can message after 21 days you join sololearn community. If you have you joined sololearn for more than 21 days, then you should contact sololearn.
Sololearn email: [e-mail]
Please use tags correctly.