Baumatic b180 oven
The oven cabinet is likely built for several different models, which means that the case could have been built with an extra hole or two that aren't used on your model. This a normal manufacturing technique for mass-product factories.
I see from the Baumatic website that several of their models do use a meat thermometer probe, but even if you bought a probe you couldn't use it your oven. Your model doesn't have the correct circuit board and control panel that the oven needs to use the probe.
In any case, if you need to order parts from the manufacturer or would like a downloadable Owners Manual for your model, they are available at this website link:
Hope that helps! ;)