How to build a snap for Qt 5.6+ with WebEngine

Ubuntu (especially build servers used canonical) don’t have this Qt version, they have much older Qt.

How can I include newer Qt version with web engine libraries? Is there any sample project that does this?

you must build your package on ubuntu 18.04

ok, but how I convince Canonical build servers to build on ubuntu 18.04?

no, the servers are still running on 16.04

you can not install yourself an ubuntu, instead you can use the LXD container