I'd definitely recommend him to everyone for any issue with 3CX or VoIP.
Fund the project upfront. Rakib gets paid once you are satisfied with the work.
Delivery time starts when Rakib receives requirements from you.
Revisions may occur after the delivery date.
In this step, you will submit your requirements, and we will discuss the best way to approach.
I'll design a demo website according to your requirements, and you will provide a review about modifications, if any.