There is no such thing. You need to do metalworking on the AR15 receiver in order to fit the automatic parts into it. A gunsmith can do it with a machine shop but it requires metalworking tools, not drop in parts. The receiver was intentionally designed to be similar to the fully automatic M16 except that it is made in a way that it does NOT to have space in it for automatic fire components. That was intentional in its design as it was designed up front to be a civilian/semi-automatic version of the M16.
There ARE drop in parts like that for the semi-automatic versions of the AK47 and the FN FAL, and for that reason those rifles are prohibited in Canada. Similarly the RCMP recently determined that replacing parts in the FN SCAR would make that rifle automatic as well, and so classed it as prohibited. The AR15 is not prohibited precisely because there is no simple way to make it a fully automatic rifle without making significant modifications to the receiver itself.