[TYPO3-dev] using composer inside extension

[Thomas Mammitzsch]

hi list,

i have an extbase extension written for 4.5. It uses a composer library 
and worked nicely in 4.5. Now i try to migrate to 6.2 and i cannot 
install that extension because Extensionmanager says that my extension 
depends on "endroid/qrcode" which is not present in the system. In fact 
it is there inside a vendor directory inside my extension.

To keep it short, how can i use composer packages inside an extension in 
6.2?

regards, Thomas