Opening move of a pawn

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rolest

Just a quick question.

I have a pawn that I have not moved.

Two spaces forward my opponent has a Bishop.

Can my pawn take his bishop on this opening move or can a pawn only capture on a diagonal.

I believe that on the opening move this is allowed, my opponent believes that this can't be done.

Thanks in advance for your advice.

rolest

Thank you very much for the quick response.