From USPS News Link:
Starting April 12 a new option for postage purchases will be rolled out to USPS Self-Service Ship and Mail Centers(SSSMCs) — formerly called Automated Postal Centers. The roll-out will continue through Sept. 30, when all SSSMCs will be equipped to sell Print On Demand First-Class Mail Forever postage.
After the upgrade, postal customers will be able to buy as few as one or as many as 100 stamps ― as well as choose from six different stamp designs. A minimum purchase of $1 is required. The postage won’t be denominated and will be sold at the current First-Class 1-ounce rate.
The Print On Demand First-Class Mail Forever postage will replace the First-Class stamp sheets currently available at SSSMCs. Click here to check updates and schedules regarding the upgrade.