Razer Synapse

Imagine me having Razer keyboard and mouse since like 2-3 years. I changed my PC, and now I need to add products in Razer synapse. How am I supposed to do it without the date of purchase? I certainly don't have it, and won't find it. I don't really care, it's just for the keyboard to be static at night so I can see the fuc**** letters when I type. Any solutions or is it some bullshit that I can't overcome? #razer1love