I am looking for a good api with c# support for bitcoin as payment method in my web site.

My purposes from this api is :

1. Create unique btc address for each order
2. Deposit job with CallBack url
3. Withdraw job
4. Minimum limits of requests

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Firstly i tried to use BitcoinLib library.
But i have two problems about it :
1. I do n'r want to download big size of bitcoin core in my local machine & in my server.
2. I could n't find good examples for my purposes related to BitcoinLib library.

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Secondly i find this third party api : 
BitGo
It was perfect and can handle all my jobs.
But i have one problem about it :
1. I can not run "sendcoins" event and make transactions in c# because build-sign-send jobs in this api need express environment of BitGo and my c# library can not handle it.

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Please introduce me a good api for those purposes!
Alao tell me can BitcoinLib handle those jobs.
If yes, How???