Yes, you can pay in the USA. More information here https://us.meest.com/en/services/service/parcels-and-cargo
Most likely, you can pay and call a courier (for large cities in Ukraine) through your personal account on the website and / or in the phone application, but if you need to arrange the parcel at the department, they will need to pay on the spot. Specify in meest-express by phone or write to them in support
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