Opencart Currency Update 3

It is necessary on the site opencard 3 to make an automatic update of the exchange rate used on the site.

Now on the opencard update of currencies from yahoo,but they have stopped supporting many platforms, including opencards and auto-renewal does not work.

I wanted to put myself in the folder public_html/mysite/admin/model/localisation/currency.php and change the api from yahoo to https://openexchangerates.org/api/latest.json?app_id=577c52691c174a9a9b7373ace3998d55, but it does not work.

Who will be able to help solve this problem, synchronize the stores currencies on api with good service and add a few more cryptocurrencies to the site