Sorry there is no internal upgradability in any of the newer MacBook Air/Pro’s!
The last fully upgradable MacBook Pro was the 2012 unibody models, the 2012 through 2015 retina models only offered a serviceable SSD drive, RAM was soldered! The 2016 TouchBar and newer have no upgrades. Only the short run of the 2016 & 2017 13” Fn models offered a serviceable SSD but it was very different from the older models and no one offers a replacement.
What you buy is what you get! If the think you need more RAM or storage buy it now!
Storage can be added externally via the USB-C/Thunderbolt connection.
For reference here’s the M1 Mac Mini logic board which is very similar to the MacBook Air & MacBook Pro models