Cookies are one of those rare foods that most diets can agree you shouldn't eat, so that doesn't really have anything to do with keto. The only space for debate about cookies is whether you should have little or none (other than for high-power people who need to cover an energy deficit, which sounds like it would be a nice problem.)

I've done keto a handful of times and found some really great snacks. Low carb cheesecakes, macaroons, peanut butter cookies, brownies with walnuts. They certainly don't taste as good as the regular version but they'll fill a craving.

Typically you're swapping flour for almond flour and sugar for erythritol.

One cup almond flour, one quarter cup erythritol, 3 tablespoons of butter, a tablespoon of cinnamon, half a tablespoon of vanilla, bake at 350 for 12 minutes, let cool for a half hour. Keto cookies.

I used cookies to mean "generic sweets", as opposed to fruit. I don't particularly like "actual cookies".

I'm in France, so the only time I've seen beef jerky in my life was when some dude I used to know brought some from the US. Furthermore, I'm really not sure if we have anything similar over here.

Note, I said I wasn't doing keto (never have) so I don't specifically look for no-carb options. I just realize that those foods are more like "cravings", so they won't make me eat less during the regular meals. If I want to reduce my calorie intake, I need to cut somewhere. So I usually look into cutting the calories of the snacks. While I love almonds and other dried fruits (and their butter), they typically have a lot of calories. IIRC, pistachios have something like 600 kCals and I can easily eat way too many.

Beef jerky is just a form of cured meat. You can also eat salami :-)