I wanted to find out is it possible to send a fax while using the Obi202. I'm asking as I see a lot of user online stating that fax over VOIP will not go thought correctly
Faxing over VoIP tends to be hit or miss in the general case. Solutions and ITSPs that support T.38 are more likely to be successful (the OBi devices can do T.38 if configured appropriately, not all ITSPs may do T.38). There are ways that one can improve the odds for other providers, but it is definitely going to be hit or miss.