Can i get hpv warts on anus even tho i'm always the top and never receive anal sex?

Possibly: Rubbing against warts can transmit them.

Yes indeed: As your question implies (and you seem to know), anal warts are most common in people who have had anal sexual exposure. But they're not rare in sexually active persons who have never had anal sexual exposure, including both women and strictly heterosexual men. It probably happens because HPV spreads along the skin from the genital area, or by finger contact after touching the genital area.