How to define particle outlet boundary in ABAQUS SPH

Hello, I am trying a very simple example of water sloshing using abaqus SPH. Please see the attached inp file. I try to set one boundary of the tank to a particle outlet boundary so that once my SPH particles reach that boundary, it will be deleted automatically. I modified the keywords in **BOUNDARY CONDITIONS section, added the following lines:

** -----------------------------------
*PARTICLE OUTLET FLOW, BOUNDARY CONDITION=NONREFLECT
*PARTICLE OUTLET, NAME=Outlet,TYPE=SURFACE,SURFACE=tank-1.Surf-1
**------------------------------------

However, when I run the data check, it aborted with error:

"No element sets found on *PARTICLE OUTLET option for Particle Outlet OUTLET.

Parameter outlet is required."

The above modification was done followed:

"https://help.3ds.com/2020/english/dssimulia_established/SIMACAEKEYRefMap/simakey-r-particleoutletflow.htm?ContextScope=all#simakey-r-particleoutletflow"

and

"https://help.3ds.com/2020/english/dssimulia_established/SIMACAEKEYRefMap/simakey-r-particleoutlet.htm?ContextScope=all#simakey-r-particleoutlet"


Anyone could help me modify the keywords?

Appreciate it!