Is their a way to implement another payment method beside paypal? What about credit card/ debit card? Is that a possibility?

First of all, nowadays PayPal = credit card.
What I mean is that even if the customer doesn't have a PayPal account, he can still pay with Credit Card. Of course YOU (the Lms administrator) have to have a PayPal account.

That being said, Forma Lms only natively supports PayPal out-of-the-box.

If you want something more or different, that usually entails integrating with a third-party e-commerce application, such as Magento or Prestashop or whatever you want.
Integrating means SSO, users synch, products synch, and many other things.

Moving to feedback

Thanks Max

Which E-commerce solution do Forma use?

90% of our customers use PayPal to sell their courses

One of them recently asked us to integrate Prestashop