Dear Inaba, thanks for your question.
Yes, selling subscription products alongside normal one-time products is possible with Shopify on Wallee. This is done by using our Wallee Subscription service alongside with Charge Flows.
You can find our documentations for both here:
Basically you need to import your shopify products and variants into wallee, and then setting up the variants which define the type of recurring payment.
To use subscriptions, you need to get sure that the payment service provider (PSP) you are using and the payment method you want to use with it do support it. (usually credit cards)
If the Payment method has this feature then you can use it for subscriptions:
If you do not have a contract with a PSP yet, you can see a list of all supported ones here:
As not all are accepting your country, you need to check which one support it. You might want to check "First Data" or "Braintree".
Let me know if anything else is unsure.
With friendly greetings