Selling services, and without cart !?

[Dragonic]

Hello,

I'm a beginner with Joomla and Virtuemart, and I have to implement a payment system (HeidelPay) for a website at work.

I have two problems! By default, it seems Virtuemart is configured (from what I see with the example) with a basket and selling physical products. However I wish to sell a service, and I cannot find information about it.
(I found the next topic, which does not help much: https://forum.virtuemart.net/index.php?topic=75176.0 )

The second point is that I do not want a shopping cart system. In fact I would like to get directly to the purchase page if I choose the service on the website.

Could you help me by explaining in some details how to achieve these results? And if it's possible ^^?

thank you in advance !