Cubase Dongle not working

Hi Hoping someone can help me here. I have Macbook Pro and Cubase 10.5 . The set up worked before .I have not used it for some years and now have the time and so excited to get back into it and the dongel is not working . It flashes light 4to 5 times then goes out and I try to open Cubase and it says ‘No valid license found’. Help. Look forward to your replies Thank you in advance. Skybo

Hi,

Follow these instructions, please.