Sorry to ask – iTunes Feed

I have looked through all the forum questions on this topic already and really am no closer to an answer than I was before I started so I apologise for asking ‘silly’ questions that have probably been answered elsewhere but I still can’t make my new iTunes feed work in WordPress.
It is all VERY confusing.

I have had to change iTunes feeds!

My new feed is validated OK, but when I have tried to put the <itunes:new-feed-url>
into the feed_rss2.php file, it doesn’t validate anymore.
I have put it right under the <channel> tag but this just devalidates the feed.

Do I use that specific tag <itunes:new-feed-url>
or
<itunes:https://footytalk.com.au/?feed=podcast&gt;

(I have tried both to no avail)

I am reading things like
“You should set your web server to return an HTTP 301 response and redirect when receiving a request for the old feed.”
but this means nothing to me. How do I do this.

My old podcasts prior to the change still show up in iTunes but not the new ones (am using Podpress btw) so am pretty well lost.

There are a lot of questions about this in the forums so I apologise again for doubling up, but all the information I read hasn’t been successful in helping me get my new feed up and running in iTunes.

Thanks to anyone who can help me make head and tail of this connundrum.

regards