Can we use "as per your asking" when replying to queries?
That sounds like something a non-native speaker would cobble together. It does not sound very good, and not for just one reason alone.
For one thing, as per is redundant for just a simple per.
But that isn’t the worst thing, which is asking doesn’t work well as a count noun here. Neither does ask. That’s because we already have a word for that which is much more commonly used. The whole thing should probably just be:
per your request
That’s still a bit funny-sounding because per is super-formal, but it sounds less bad than the original.