Air carrier Captain reported a loss of control on a taxiway in slippery conditions; while remaining on the taxiway. The Captain requested a tow to an area with better traction; and proceeded to the gate.

Narrative

After landing; we experienced good braking action on the runway and were able to clear it without any issues. Once off the runway; ATC instructed us to turn onto a designated taxiway. As I slowed down to make the turn; the airplane began to lose traction due to the slippery conditions on the taxiway. When I applied the brakes; the plane did not slow down as expected; and it continued moving slowly in a straight line instead of turning as intended.I momentarily regained traction and was able to reduce speed further. However; as I attempted to bring the airplane to a complete stop; the slippery surface caused another loss of traction. This resulted in the plane veering slightly to the right; approximately 30 to 45 degrees off the taxiway centerline; before we came to a full stop. Throughout this event; all wheels and the entire airplane remained within the paved area of the taxiway.Given the continued lack of traction and to ensure safety; I decided not to move the airplane any further and requested assistance for towing. We were safely towed to an area with better traction. Once in a more stable area; we resumed taxiing and proceeded to the gate without further issues.The slippery taxiway conditions significantly reduced traction; making it challenging to maneuver the airplane and bring it to a complete stop.In extreme weather conditions; it is better to slow down and not assume the taxiway conditions are similar to the runway conditions. If ATC is aware of this; they could relay that information to us in the air or as soon as we land so we can be more cautious and increase our situational awareness.