thanks for your message.
To setup Wallee, you will first need to install the wallee app in Shopify, I can see that you have already done this.
After that, you need to install the payment gateway for each payment method you want to use and enter your Shopify Integration Credentials (ID and Security Token)
Please see the documentation about how to install:
I see that you already configured your BSPAYONE account and some payment methods.
Once you have set up the payment gateways on wallee and activating them on the payment gateway section in the backend, you should be ready to test.
For credit cards, you may need to disable other credit card integrations to get wallee to work.
I hope this helps,