When starting to type in a station name (starting at the 3rd char), it will suggest station names, and you can just tab them to select.
I made a txt file with all station names I found on the NMBS website. I hope it’s up to date, and if there are any stations missing, please report. 🙂
The station names depend on their location within Belgium. Flemish stations are Dutch only, Walloon stations French only. Everything inbetween (e.g. Brussels) is in both languages.