You’re massively out of date, unfortunately. If you switch to FreePBX 13 (which will involve updating everything) you can then start looking at the new REST API module, which has only recently been released as Open Source. You could add to that.
Or, there’s UserMan, which integrates natively with Active Directory?
Right, I thought that someone already develop and will be glad to share it with us but this is not the situation.
We probably will develop this, if I will can I will share it with you
If you develop this, be sure to share it with both your CRM provider and us. Be sure to mention the version of FreePBX you are using - there are interfaces to older version of FreePBX that aren’t supported in the newer versions.