https://mycryptocheckout.com/doc/developers/:
“MyCryptoCheckout offers a PHP API that you can use to make your own integrations. The source is available from the MyCryptoCheckout API GIT repository.The API can be included in your PHP project via the MyCryptoCheckout API composer package.”
—
https://packagist.org/packages/mycryptocheckout/api:
Installation
composer require mycryptocheckout/api
I hope that helps.
And when i install the api?