There are two options available for you. The most cost effective depends on whether you intend to make any changes to the intro/outro/intermission in the coming years.
The first option is to buy three licences (one for each of the above) and that’s all you’ll need. But if further down the line, you need to make a change to any of those (like a new voiceover) then you’ll need a new licence for any updated versions.
The second option is to buy one licence for the series which will last for a year (or 52 episodes, whichever comes first), at which point you will need to buy one new licence every year. With this option, the one licence covers you to use the music anywhere and as often you like within that one podcast series.
Please contact Envato support to find out which type of licence you need to buy. According to a customer in this thread, if the podcast is going on Spotify, broadcast licences are required, although in my opinion, it’s not clear why, and to my knowledge, Envato haven’t mentioned in the licence wording which one they expect you to purchase.
You can open a support ticket here:
If you do find out, please do let us know what they say. It would be good to know.