Great suggestions from @tweinzapfel to also look at Power Automate as an option here.
In addition, in the writeup that the JMAP team did for Challenge #12, I provided a detailed section on how I called the Opencage API from an R script in PQ to obtain Lat/Long coordinates for the airports in the dataset. Obviously, a different API, but same general approach I think would work well here.
Note: I wasn’t familiar with What Three Words before readiing your initial post, but that’s super cool.
Also looping in our resident geospatial wizard @Paul here for his advice/input.
And if you’re interested in doing this via Python call from PQ instead of R, we can check with @gmh1977 , @gjmount and/or @AntrikshSharma.
Amost too many options here… 
- Brian