PXE Server on FreeNAS

Not sure if this question belongs in Networkng or Software?

I have set up a share on a FreeNAS box with a load of ISO files. Now I would like to be able to boot these on an old laptop via PXE but I don’t know how to do this. There is a network boot option on the laptop and I understand that I need a TFTP server on the FreeNAS box but I can’t see an option for that.

I am new to FreeNAS and have not used Unix for the last 15-20 years so I am very rusty with this stuff.

Any advice appreciated. Thanks, Leo.