Which shipping carrier do I give this return package to?

I’m returning a cosplay outfit to this vendor from Amazon.

I’ve returned stuff before through Amazon but this one is confusing becuase the return label to put on the package isn’t clear to me. Usually it says like UPS or FedEx, but this one doesn’t say anything like that.

Now – I assume it’s DHL only because I used expedited shipping and the package came through DHL – but wouldn’t the return label say DHL on it then??

I tried contacting the seller directly but Amazon is a bitch to figure out – I can only “contact” them in the sense that I click on “return item” or whatever and it sends an automated return item request. I tried emailing some marketplace email in the Amazon email that was sent to me, but they haven’t replied in several days.

This is what the return label looks like:

https://ibb.co/i8mwwG

I really don’t want to have to pay for return shipping if I don’t have to, so I want to make sure I know which carrier to use.