My recollection is that the old Oxford Dictionaries site had entries in both American English and "British & World English", which could be accessed through different urls.
Lexico has British & World English entries, whose addresses have the format https://www.lexico.com/en/definition/
followed by the headword. Is there any way to access Oxford's American English entries through the Lexico site? Much of the information is the same, but the American English pronunciation guides are often different.