Install the bluez snap via:
$ snap install bluez
The snap is being downloaded and installed. Observe that the snap has been installed like follows:
$ snap install bluez bluez 5.37-2 from 'canonical' installed
The naming scheme for the bluez snap includes the current BlueZ version being packaged in the snap (5.37 in this case) and the revision of the snap itself (2nd in this case). Whenever the snap is updated but still provides BlueZ version 5.37 the last digit will be incremented.
The above output informs that BlueZ 5.37 has been installed on the system. This effect is equivalent to typing
$ sudo apt install bluez
on a classic Ubuntu flavor that you run on your desktop or laptop computer.
Again, let's list the interfaces:
$ snap interfaces | grep blue bluez:service bluez:client :bluetooth-control - $
This time it lists the bluez:service slot and the bluez:client plug that are provided by the bluez snap itself.