Is it possible to use GPL and LGPL libraries for a web service for commercial purposes?

Question

Licenses for software and other works

It is required to develop a backend for a commercial web service. It is advisable to use Qt for this. Can I do it and how? Ultimately, although the service will be used for profit, the backend itself, written using Qt and Qt Creator, will not be distributed in any way. If it's not difficult, please answer with links to the texts of licenses, but I will be glad for any advice. Thanks in advance.

Answer 1

Well, since they called - the first question is why Qt for the back? Why not C#?
On the topic - for commercial use, you must purchase a license, alas.