1 Uncle Owen: Luke, take these two over to the garage will you? I want them cleaned up before dinner.
2 Luke: But I was going into Tosche Station to pick up some power converters!
3 Luke: I don’t get paid enough to do all this work!
4 Uncle Owen: Okay, fine. I'll give you an extra 20 Imperial credits a week.
5 Caption: Star Wars: The Raise of Skywalker.

I debated what currency to use in this strip.

Canonically we know when Anakin was a boy on Tatooine that, "Republic credits are no good out here," and, "No, they won't," do fine, no matter what a Jedi says.

However, 32 years later, when Luke is whining about Tosche Station, things may have changed. Han demands "ten thousand" to take Luke and Obi-Wan, and two droids, no questions asked, to Alderaan, but they never mention ten thousand what in the film. However, Wookieepedia states that they were negotiating in credits (by that time, Imperial credits), which is about as canonical as you can get (since Wookieepedia editors are scrupulous about canon sourcing). Luke then proceeds to sell his speeder for some cash to provide the 2000 deposit that Obi-Wan negotiates with Han - so presumably he sold it for Imperial credits.

The other option would have been to use the currency used by the Hutts, who control much of the economy of Tatooine. They use wupiupi. However, it's a fairly safe bet that 90% of Star Wars fans have never heard of wupiupi, and using it casually in a comic strip might cause enough confusion to dilute the joke.

So I chose to use credits, because at least everyone can instantly understand it, even if it might not be what Owen would actually pay Luke.

If he paid him at all.