Model numbers would be useful, at least for the TV. Can't find any info on what connections any Telefunken HTS has. Only a picture of the back of the main unit would help.
General answer would be to connect the optical audio output of the TV to the optical input of the Telefunken with a toslink optical cable. If the HTS only has a stereo aux input you would need an optical to analog audio converter,
If the TV has a headphone jack that would connect to the HTS without a converter.