How to build Debian packages

Please describe.
The source tree has a debian directory with control.tpl.

Describe the solution you'd like
Description how to build Debian packages from source got from git clone https://github.com/rustdesk/rustdesk-server.git.

Describe alternatives you've considered
debuild, screenshot follows:

stappers@messer:/usr/src/rust/rustdesk/rustdesk-server
$ debuild
debuild: warning:     debian/changelog(l4): found start of entry where expected more change data or trailer
LINE: rustdesk-server (1.1.13) UNRELEASED; urgency=medium
debuild: warning:     debian/changelog(l4): found end of file where expected more change data or trailer
 dpkg-buildpackage -us -uc -ui
dpkg-buildpackage: warning:     debian/changelog(l4): found start of entry where expected more change data or trailer
LINE: rustdesk-server (1.1.13) UNRELEASED; urgency=medium
dpkg-buildpackage: warning:     debian/changelog(l4): found end of file where expected more change data or trailer
dpkg-buildpackage: error: cannot read debian/control: No such file or directory
debuild: fatal error at line 1182:
dpkg-buildpackage -us -uc -ui failed
stappers@messer:/usr/src/rust/rustdesk/rustdesk-server
$

Notes

At https://www.debian.org/doc/debian-policy/ch-source.html#s-readmesource is this text:

debian/README.source may also include any other information that would be helpful to someone modifying the source package. Even if the package doesn’t fit the above description, maintainers are encouraged to document in a debian/README.source file any source package with a particularly complex or unintuitive source layout or build system (for example, a package that builds the same source multiple times to generate different binary packages).

Start by inspecting debian/control.tpl and the source package layout, then reproduce the reported debuild command from a fresh git clone. Use debian/README.source as the likely documentation location; document the required preparation, build commands, and the successful package output.