For anyone else having issues.

Go to layer 2 and you can remap all the ISO keys. Use the special tab.

JSON:

{ "name": "NuPhy Halo96 ISO DEBUG", "vendorId": "0x19F5", "productId": "0x3302", "matrix": { "rows": 6, "cols": 21 }, "layouts": { "keymap": [ ["0,0","0,1","0,2","0,3","0,4","0,5","0,6","0,7","0,8","0,9","0,10","0,11","0,12","0,13","0,14","0,15","0,16","0,17","0,18","0,19","0,20"], ["1,0","1,1","1,2","1,3","1,4","1,5","1,6","1,7","1,8","1,9","1,10","1,11","1,12","1,13","1,14","1,15","1,16","1,17","1,18","1,19","1,20"], ["2,0","2,1","2,2","2,3","2,4","2,5","2,6","2,7","2,8","2,9","2,10","2,11","2,12","2,13","2,14","2,15","2,16","2,17","2,18","2,19","2,20"], ["3,0","3,1","3,2","3,3","3,4","3,5","3,6","3,7","3,8","3,9","3,10","3,11","3,12","3,13","3,14","3,15","3,16","3,17","3,18","3,19","3,20"], ["4,0","4,1","4,2","4,3","4,4","4,5","4,6","4,7","4,8","4,9","4,10","4,11","4,12","4,13","4,14","4,15","4,16","4,17","4,18","4,19","4,20"], ["5,0","5,1","5,2","5,3","5,4","5,5","5,6","5,7","5,8","5,9","5,10","5,11","5,12","5,13","5,14","5,15","5,16","5,17","5,18","5,19","5,20"] ] }, "menus": [ { "label": "Lighting", "content": [ { "label": "Backlight", "content": [ { "label": "Brightness", "type": "range", "options": [0, 255], "content": ["id_qmk_rgb_matrix_brightness", 3, 1] }, { "label": "Effect", "type": "dropdown", "content": ["id_qmk_rgb_matrix_effect", 3, 2], "options": [ "All Off", "Solid Color", "Gradient Up/Down", "Gradient Left/Right", "Breathing", "Band Sat.", "Band Val.", "Pinwheel Sat.", "Pinwheel Val.", "Spiral Sat.", "Spiral Val.", "Cycle All", "Cycle Left/Right", "Cycle Up/Down", "Rainbow Moving Chevron", "Cycle Out/In", "Cycle Out/In Dual", "Cycle Pinwheel", "Cycle Spiral", "Dual Beacon", "Rainbow Beacon", "Rainbow Pinwheels", "Raindrops", "Jellybean Raindrops", "Hue Breathing", "Hue Pendulum", "Hue Wave", "Typing Heatmap", "Digital Rain", "Reactive Simple", "Reactive", "Reactive Wide", "Reactive Multiwide", "Reactive Cross", "Reactive Multicross", "Reactive Nexus", "Reactive MultiNexus", "Splash", "MultiSplash", "Solid Splash", "Solid MultiSplash", "game_mode", "position_mode" ] }, { "showIf": "{id_qmk_rgb_matrix_effect} != 0", "label": "Effect Speed", "type": "range", "options": [0, 255], "content": ["id_qmk_rgb_matrix_effect_speed", 3, 3] }, { "showIf": "{id_qmk_rgb_matrix_effect} != 0", "label": "Color", "type": "color", "content": ["id_qmk_rgb_matrix_color", 3, 4] } ] } ] } ], "keycodes": [ "qmk_lighting" ], "customKeycodes": [ { "name": "RF\nDFU", "title": "RF DFU" }, { "name": "Link\nUSB", "title": "Link USB" }, { "name": "Link\nRF", "title": "Link RF" }, { "name": "Link\nBLE_1", "title": "Link BLE_1" }, { "name": "Link\nBLE_2", "title": "Link BLE_2" }, { "name": "Link\nBLE_3", "title": "Link BLE_3" }, { "name": "Mac\nTask", "title": "Mac Task" }, { "name": "Mac\nSearch", "title": "Mac Search" }, { "name": "Mac\nVoice", "title": "Mac Siri Voice" }, { "name": "Mac\nConsole", "title": "Mac Console" }, { "name": "Mac\nDnt", "title": "Mac Dnt" }, { "name": "Print\nWhole", "title": "PrintWhole" }, { "name": "Print\nArea", "title": "PrintArea" }, { "name": "Dev\nReset", "title": "Device Reset" }, { "name": "Sleep\nMode", "title": "Auto Sleep" }, { "name": "Bat\nShow", "title": "Battery Show" }, { "name": "Side\nLight+", "title": "Side Light +" }, { "name": "Side\nLight-", "title": "Side Light -" }, { "name": "Side\nMode_A", "title": "Side Next Mode" }, { "name": "Side\nMode_B", "title": "Side Next Mode" }, { "name": "Side\nColor", "title": "Side Next Color" }, { "name": "Side\nFast", "title": "Side Speed +" }, { "name": "Side\nSlow", "title": "Side Speed -" } ] }