Upgrade ssd of my laptop

Some MacBook Pros have upgradeable SSD and other do not. If you want details we need to know your computer's sub-model including screen size, which you can find from "About this Mac..." under your Apple menu:

Also Apple will only replace "in kind," meaning if you have a 256GB drive now, that is the only size with which they will replace it. You will be doing it yourself or paying an independent provider to do it.

Basically if your MBP is 2016 or newer, your options are extremely limited or non-existent