how to prevent a code from going down?

hi, I have three iframe amazon ad codes on my blog. The problem is that the second iframe appears below the first iframe, and the third iframe code appears below the second. I want to arrange them so that they are all on the same (invisible) “row”. i’d be so thankful if anyone can help me solve it!

i want it to look like this:
iframe iframe iframe
and not like this:
iframe
iframe
iframe

as seen at the bottom of this post:
https://www.nobalding.com/how-to-compound-minoxidil-andazelaic-solution/

thanks thanks thanks! ??