License activation problems

Hello, I’m having trouble activating my license. I bought a license for my Acer Chromebook 13 with an Intel Core i5 8250u processor. When I was paying for the license, I selected the discount option, and it gave me the option to pay $5. However, it seems that my model is not supported in that discount offer because when I try to activate the license, it generates an error that doesn’t allow me to activate the sound. I already have the driver installed, but the activation doesn’t complete. I would like your help to activate the license that corresponds to me by paying the remaining $5 so that the system gives me the final activation. I appreciate your help.