H1b first time stamping in UK

I have a question,i’m working in Uk from last 2-3 years and my h1b was processed in UK itself. my home country and citizenship is India.
I have taken appointment for my first time stamping in london itself and i got the dates as well. please suggest if it is fine or will it create any problem since i’m not doing my stamping from india

There should be no issue. You are allowed to get stamping in any US embassy as long as they allow it.