My name is John and I'm a Guru here at Shopify!
Thanks for taking the time to add your query here on our merchant forums. :)
You can check out the full list of payment gateways available in Poland for use with your Shopify store.
It doesn't look like PayU or InPost are on that list, so you would have to use one of the choices presented there instead.
Best of luck with everything here!
Good news! Both PayU and Paczkomaty InPost integrations are now available.
For Paczkomaty InPost – all you need is to install app from Shopify App Store – no coding needed!
For PayU – it's a custom solution, if you are interested – please get in touch. We can get you up and running in 1 business day :-)