The test is a tower with a level height of 10 mm and a wall thickness equal to the extrusion width for a nozzle of 0.4 mm.

To change the layer temperature in PrusaSlicer, go to PRINTER SETTINGS - USER G-CODE - G-CODE, BEFORE LAYER CHANGE by adding a line of code with a comment:

;decrease 5, degrees every 10mm, with 0.0mm intro M104 S{250 - (5 * int(((layer_z - 0.0)/ 10)))}

Based on the publication https://www.prusaprinters.org/prints/38895-temp-tower-prusaslicer-02mm-layer-petg