How to Install a Techno Flange
It is made to glue to 3" or 4" drain pipe. I can't tell for sure but it looks like it glues over 3" or into 4".

You need to make sure the flange and glue are compatible with your pipe. If the pipe is white it is probably PVC, make sure you have the PVC flange and glue. If your pipe is black it is ABS, make sure you have...blah, blah, blah.

The flange may be set to rest on top of the finished floor or flush with the finished floor. It needs to be secured to the floor as well (note the screw holes). It might be easiest to glue it on and fasten it to the sub-floor with stainless screws, then tile up to it. The tile won't need to be perfect because the toilet should hide the immediate area.