Do I need a seperate headphone amp WITH my audio interface?

I have a Steinberg UR22 Mk2 interface and want to get some new heapdhones. Either AKG K702s or Sennheiser HD600s.
Would my UR22 be able to drive these, or would i need to get a seperate headphone amp

The headphone out should do the job.

I am planning to buy a pair of Beyerdynamic DT77o Pro - 250 Ohm model… with only connection to my Steinberg UR22 MKII audio interface. Understand that 250 Ohm model require additional headphone amp but i wish i do not need to invest the amp. Can the UR22 drive this 250 Ohm headphone well?

Ask your dealer. Though I would recommend you buying a soundcard where you shouldn’t add extra devices for plugin an earphone.