Landing page (html&css) + Yandex.Checkout, integration?

Question

Landing pages

Help me to understand.
There is vds, a static business card site is spinning on it. I have a Yandex.Checkout account.
I want to make a landing page (html+css) with a payment button. The payment amount is fixed. I need data from the user: name, phone number and delivery address.
I re-read it in various ways on the Yandex cash desk, but I can’t catch up .. too confusing for a person with basic skills and without any examples of integration.
PS I did not find real examples with statics in articles or YouTube ..