Через JS они там догружаются.
curl 'https://www.banki.ru/products/currency/ajax/quotations/history/cbr/' -H 'Content-Type: application/json' -H 'X-Requested-With: XMLHttpRequest' -H 'Origin: https://www.banki.ru' --data-raw '{"currency_id":840,"from":1609362000}'
{
"currency_id": 840,
"history": {
"1609362000": 73.8757,
"1609448400": 73.8757,
"1610398800": 74.5157,
"1610485200": 74.2663,
"1610571600": 73.5264,
"1610658000": 73.7961,
"1610744400": 73.5453,
"1611003600": 73.9735,
"1611090000": 73.7243,
"1611176400": 73.355,
"1611262800": 73.3694,
"1611349200": 74.3615,
"1611608400": 74.8569,
"1611694800": 75.6354,
"1611781200": 75.04,
"1611867600": 76.1854,
"1611954000": 76.2527,
"1612213200": 75.5053,
"1612299600": 75.9051,
"1612386000": 76.0801,
"1612472400": 75.7293,
"1612558800": 75.1107,
"1612818000": 74.2602,
"1612904400": 74.1192,
"1612990800": 73.8526,
"1613077200": 73.7579,
"1613163600": 73.9378,
"1613422800": 73.3092,
"1613509200": 73.2895,
"1613595600": 73.7669,
"1613682000": 73.7755,
"1613768400": 73.9717,
"1613854800": 73.9833,
"1614200400": 73.7532,
"1614286800": 73.4747,
"1614373200": 74.4373,
"1614632400": 74.0448,
"1614718800": 74.5755,
"1614805200": 73.5187,
"1614891600": 73.7864,
"1614978000": 74.4275,
"1615323600": 74.264,
"1615410000": 74.0393,
"1615496400": 73.4996,
"1615582800": 73.5081,
"1615842000": 73.2317,
"1615928400": 72.9619,
"1616014800": 73.1019,
"1616101200": 73.6582,
"1616187600": 74.139,
"1616446800": 74.6085,
"1616533200": 75.3585,
"1616619600": 76.1535,
"1616706000": 76.1741,
"1616792400": 75.7576,
"1617051600": 75.8287,
"1617138000": 75.7023,
"1617224400": 75.6373
}
}