Firearms can be purchased online just like any other product. The only difference is that all firearms must be shipped to a dealer with a Federal Firearms License (FFL) for you to pick up.
The background check is conducted by the FFL dealer and completed by you, the actual buyer/transferee.
You will be able to choose a dealer during the checkout process.
You must contact the FFL dealer you choose to make them aware of the transfer. It is recommended that you inquire about any possible transfer fees they may charge.