How to apply a distributed load to a 1D edge?

Dear all,

I would like to apply a distributed load (pressure) across an edge within a 2D model. I know the value of the load in Newtons.

The boundary conditions of the model looks as follows (where P1 represents the edge to which the distributed load is applied):

I would appriciate any advice that can be offered on how to accomplish this.

I am using the partial differential equation toolbox to perform the structural simulation (FEA).

Thank you in advance.