Thanks for the info.
As far as the country goes, it's fine. I'm not doing it for myself. The server and the owner will be outside of my country. I'll look more into both options. Thanks again.

Thanks for the resources.
My first try was Blockchain.info's API (and its wrapper) but it requires installing a service on my PC and let's just say it wasn't as easy as it sounded like. I'm having some issues with it. However, if this is the way to go, I could install it on a Linux server and use it on my Windows server.

I've contacted BitcoinLib's owner and he said that using his library would require a lot of customization on my part. I haven't read NBitcoin's docs however I'd think that it's basically the same as BitcoinLib.

About using 3rd party service, I don't have any issues with it. But some people suggested that it might be less secure than using a wallet locally on my server. One might argue the opposite but I'm not sure which way is the best option.

Paying some small fee for this wouldn't be an issue as long as it's not a lot. I'm just trying to find the best solution and by "best" I mean a solution which requires as little as possible tampering on my side and the highest possible security for my business

Which solution would you suggest?

Thanks again.

thank you very much

Thanks for the reply. Could you suggest me another API? I'm looking for a secure wallet with transaction support.

I'm creating a website to transfer bitcoins between clients. Can I use Electrum for this? Does it have an API to allow me to create a unique wallet for each user and transfer funds between them? Any helps would be appreciated.