Karel Čapek didn’t invent the word robot, he could have used its strain in a new form at most

Is the word robot made up? No.

The stem of the word rabota (robota, do, robiti) is mentioned already in the writing Zakon sudnyj ljudem

Old Slavic (ИЗД)РАБОТАЮТ, РАБОTA
Transliteration into Latin (IZD)RABOTAJUT, RABOTA
Slovak (OD)ROBIA, ROBOTA
Czech (OD)DĚLAJÍ, DĚLNÍK

Source http://librinostri.catholica.cz/MoravaZakonSudnyj
Source juls.savba.sk/1934-35/lq.pdf