There are two floodlit tennis courts at the Nordic Arena in Toblach / Dobbiaco (1x artificial, 1x clay). It is also possible to take a lesson, but only on request.
How to reach Dobbiaco/Toblach: https://www.drei-zinnen.info/en/dobbiaco/dobbiaco/contact-and-service/arrival-mobility.html
Also accessible by public transport. The timetables are available on www.sii.bz.it.