Missing “Jumper” extension kit

Hello! Does anybody know how I can option the orange “jumper” for my extension kit? I have just moved into my new house with an existing Tado system and the I realised the boiler was constantly firing, even when the radiators were off. After some back and forth with support, it seems I need an orange jumper which is somehow missing from my system. As the extention kit is discontinued, they can’t send me a replacement part and only recommend buying a new replacement receiver, which I’m loathed to do with all the expense of moving as it is!

Any help or pointers really gratefully received.