Hi, @yto4ka78 !
Katy here from Shopify. I hope all is well with you, and welcome to our Community.
Great question! When connecting a payment gateway to your store, you will first need to ensure that it is available where you/your business is located. We have a list of all available gateway options per country here.
If 2Checkout is available in your location, great stuff! From here you will need to reach out to 2Checkout directly to create your account with them.
I understand that they do have a partnership with Payoneer as a payout method. This is something that you would need to chat with their own support team about setting up within your account. Though you may find this blog article helpful.
Once you have your account details from your preferred payment gateway, you can then login to your Shopify admin to link this to your Shopify store. This would be within your: Settings > Payment providers section. We have some info on how to do so here.
I hope this helps to point you in the right direction - do feel free to let me know if you have any questions.