The text below is copied and pasted from here
How do I download paid apps from Aurora Store?
“For paid apps, though, you need to log in to your Google account. This app lets you use dummy accounts by default, but it can’t access paid apps the same way. You need to actually buy those apps via Play Store and then log into Aurora Store with your Play Store account to download them”
(Not sure if it works like that on /e/ but think I’ve seen other posts on the forum about this.)
Also saw this in another thread on the forum :
“There may be situations when you inevitable need paid apps from the Google Play Store. In many cases you can simply use the Aurora Store to install apps you bought (just buy the app from a web browser by visiting https://play.google.com”