Pirate Ship only offers labels for USPS® parcel shipping services. If you're just trying to mail a letter, you're best off buying some cool stamps at the Post Office 😉
Why Pirate Ship does not offer stamps or postage for mailing letters
Pirate Ship is built for eCommerce shipping, so we do not offer any USPS® mail services for domestic or international, as those services are meant for letters and documents, not merchandise.
Mailing services are not available on Pirate Ship: Some of the mailing services that Pirate Ship does not offer include the following:
First-Class Mail
Metered Mail
Marketing Mail
Bound Printed Matter
Forever stamps
Certified Mail
First Class Mail International Large Envelope
Flat services
Mailing services don't include tracking: These mailing services above don't come with tracking (while the labels have a number that LOOKS like a tracking number, it isn't one). Every shipping service, on the other hand, includes tracking.
USPS may reject packages sent with mailing services: Since mailing services like First Class Mail International Large Envelope / Flat service are not intended for merchandise, USPS® will reject and return your packages if you try to use these mailing services to send anything other than documents.
You should be using USPS Ground Advantage® or First Class Package International® instead.