CR-20 PRO Cura Definition (just put this in your definitions folder to add the printer to the app: ~/.local/share/cura/3.6/definitions)

creality_cr20pro.def.json

{
    "name": "Creality CR20 Pro",
    "version": 2,
    "inherits": "fdmprinter",
    "metadata": {
        "visible": true,
        "author": "Michael Wildermuth",
        "manufacturer": "Creality3D",
        "file_formats": "text/x-gcode",
        "preferred_quality_type": "draft",
        "machine_extruder_trains": {
            "0": "creality_cr10_extruder_0"
        }
    },
    "overrides": {
        "machine_width": {
            "default_value": 220
        },
        "machine_height": {
            "default_value": 250
        },
        "machine_depth": {
            "default_value": 220
        },
        "machine_head_polygon": {
            "default_value": [
                [
                    -30,
                    34
                ],
                [
                    -30,
                    -32
                ],
                [
                    30,
                    -32
                ],
                [
                    30,
                    34
                ]
            ]
        },
        "layer_height_0": {
            "default_value": 0.2
        },
        "top_bottom_thickness": {
            "default_value": 0.6
        },
        "top_bottom_pattern": {
            "default_value": "concentric"
        },
        "infill_pattern": {
            "value": "'triangles'"
        },
        "retraction_enable": {
            "default_value": true
        },
        "retraction_amount": {
            "default_value": 5
        },
        "retraction_speed": {
            "default_value": 40
        },
        "cool_min_layer_time": {
            "default_value": 10
        },
        "adhesion_type": {
            "default_value": "skirt"
        },
        "skirt_line_count": {
            "default_value": 4
        },
        "skirt_gap": {
            "default_value": 5
        },
        "machine_start_gcode": {
            "default_value": "G28 x0 y0\nG29 z0;Home\nG1 Z15.0 F6000 ;Move the platform down 15mm\n;Prime the extruder\nG92 E0\nG1 F200 E3\nG92 E0"
        },
        "machine_end_gcode": {
            "default_value": "G91\nG1 F1800 E-3\nG1 F3000 Z10\nG90\nG28 X0 Y0 ; home x and y axis\nM106 S0 ; turn off cooling fan\nM104 S0 ; turn off extruder\nM140 S0 ; turn off bed\nM84 ; disable motors"
        },
        "machine_heated_bed": {
            "default_value": true
        },
        "gantry_height": {
            "default_value": 30
        },
        "acceleration_enabled": {
            "default_value": true
        },
        "acceleration_print": {
            "default_value": 500
        },
        "acceleration_travel": {
            "default_value": 500
        },
        "jerk_enabled": {
            "default_value": true
        },
        "jerk_print": {
            "default_value": 20
        },
        "jerk_travel": {
            "default_value": 20
        }
    }
}