There’s a few. Amythest client has one built in I believe, there’s Plebeian Market and Shopstr as well. nostr:npub1market6g3zl4mxwx5ugw56hfg0f7dy7jnnw8t380788mvdyrnwuqgep7hd nostr:npub15dc33fyg3cpd9r58vlqge2hh8dy6hkkrjxkhluv2xpyfreqkmsesesyv6e