Changing license from a PC to another

I used a license code for the Map Route Generator on another computer but now when I try to install it again on my new computer, I see that I should’ve unistall it on my previous computer, but I do not have it anymore. There’s a way that I can do it without buying this again?

Hello, I’m the author of Map Route Generator. I don’t know if you already fixed your problem however the license works on up to 10 different systems. If you need assistance please contact me on [email removed]
Thank you