Touch Bar MacBook Pro models have non-upgradeable SSDs, seemingly under-sized batteries - 9to5Mac
Amazon.com: INDMEM NVMe PCle SSD 512GB 3D TLC Flash Hard Drive with Tools for Upgrade 2016 2017 13" MacBook PRO A1708(EMC 2978/3164 Non-Touch Bar Models(Late 2016-Mid 2017 Year) : Electronics
Photo tutorial: Upgrading a MacBook Pro with an SSD
MacBook Pro 13 A1502 How to install M2 SSD upgrade - YouTube