Apple has determined that, in a limited number of 13-inch MacBook Pro (non Touch Bar) units, a component may fail causing the built-in battery to expand. This is not a safety issue and Apple will replace eligible batteries, free of charge. Affected units were manufactured between October 2016 and October 2017 and eligibility is determined by the product serial number.
You can use the serial number checker at the link below to see if your device qualifies for this program. If your 13-inch MacBook Pro (non Touch Bar) has an eligible serial number, Apple will replace the battery, free of charge.
If your devices qualifies, you can get it fixed at an Apple Authorized Service Provider, an Apple Retail Store, or via the Apple Repair Center.
More details at the link below.