In an indirect way there is, if you use the off-line registration process (not through the avastUI), you then receive an email with your registration key.

That said:
@ crgibson
If you copy and paste that key, ensure that you don’t copy any trailing spaces.

You can register directly from the avastUI > Settings > Registration - if you have register this way - that should be it done and dusted. The Insert activation code or Insert license file options are if you wish to upgrade the free version to one of the paid versions.