Here is a tutorial by Valerie. Hope this can help you How To Create Clickable Affiliate Banners

Go to Airplane icon, banner, copy the HTML CODE (not the affiliate link). Insert the Html code into your website using the Text editor, not the visual editor. Remember to save. Now it should be working.

Are you talking about WA banners? If so, all you do is click on the airplane and click on banners. Select the banner you want, copy the code and then go to your post, click on text find where you want to add your banner paste your code, I always then select open in a new tab, click on visual again and your banner should be there. As others have said, there are training videos also if you want to search for one just type in what you want at the top of the page where you can ask a question and you should get a list of trainings. Be specific because there are hundreds of videos and trainings. I hope this helps.

If you go to affiliate boot camp, there are instructions on how to place WA banners. Is the WA banner what you are looking for?

Best I can tell you is check out one of the videos you may have one of the options done wrong or try it on a actual computer