I admire your belt and braces concern on fitting LED indicators but you typically have either an electronic flasher unit to work with these LED's OR resistors across them to simulate the current draw of standard filament bulb, not both.
Richard
2018 Roadster 3.7 1966 Land Rover S2a 88 2024 Royal Enfield Guerrilla 450 1945 Guzzi Airone