Hi @R_X
If propellerads will provide you iframe tags, you can run these as your “house ads” in the discourse ad plugin, or directly in your themes (or in a theme component).
The key is to get iframe tags because these are much easier to run than script tags in Ember applications.
FWIW,
I just did a quick search for you @R_X and it does seem (unless things have changed) that PropellerAds will NOT provide you iframe tags.
See for example:
If this is indeed the case, you will probably need a discourse plugin developer to help you because getting third-party script tags to work with Ember can be quite tricky.