=IMPORTXML("http://www.cbr.ru/scripts/XML_daily.asp?date_req=11/05/2020"; "//ValCurs/Valute[CharCode=""USD""]/Value")
=IMPORTXML(
"http://www.cbr.ru/scripts/XML_daily.asp?date_req=" & TEXT(A2;"DD/MM/YYYY");
"//ValCurs/Valute[CharCode=""USD""]/Value"
)