Yes, apt can install deb packages. In fact, apt is the preferred package manager on Debian-based operating systems including Ubuntu, Linux Mint, and others. To install a .deb package using apt, you can run the following command in the terminal:
sudo apt install /path/to/package.deb
This command will install the specified deb package along with its dependencies. However, it's worth noting that installing packages from outside trusted repositories can potentially introduce security vulnerabilities into your system. Therefore, it's important to exercise caution when installing packages from unknown sources.