You need to remember that budget airlines throughout the world totally detest 'screenscraping' websites, such as Skyscanner, and actively seek to prevent their fares from appearing on such sites. (Budget airlines want you to go via their own websites as they make very little profit, and might even make a loss, on selling seats. They need to get travellers to buy 'extras', such as insurance, accommodation, car hire, etc, which is where they make most of their profits. People buying through screenscraping sites don't get presented with ads for such extras). So fares from airlines such as Ryanair, easyJet, Wizz and their Asian or African counterparts often aren't to be found on screenscraper sites.
So the best way to get the cheapest fares is often to go to the Wikipedia pages of the departure and arrival airports and use them to try to plan a route via a point that's served from both of those airports by budget airlines. Then go to the relevant airlines' websites to see if the conections work out well and, if so, to book directly on those sites. It can be hard (and sometimes frustrating) work but it can end up saving you a lot of money!