The 130XE has two display outputs, as you've probably already seen.
The easiest one to use is a VHF/UHF TV output, which should go to a TV that supports analogue TV standards. It should be relatively easy to find a TV antenna cable; you can combine it with the output of a set-top box, if needed, with a UHF Y adapter. You'll need to tune the TV to whichever frequency the Atari puts its signal on - probably channels 4 or 36, depending on which PAL region it was sold for.
There is also an output compatible with composite-video, but it appears on a non-standard port based around a 5-pin DIN plug. Many TVs will accept composite video on a yellow RCA jack, even if they don't support analogue RF input. The trouble is obtaining a cable between Atari 5-pin and RCA. The plugs themselves are easy to obtain, so you could make one yourself, by cutting one end off an RCA-RCA composite video cable.
You might have more luck searching for Atari XL-series cables; they're essentially the same as on the Atari XE series, but the XL series is better known. The 800XL might be the most popular model to use as a search term.