How do I change Office 365 to Semi-Annual Extended Channel

Hi,

So, I was using Office 365 in Semi-Annual Channel version 17XX, but on the 10th Microsoft released the version 18XX to this channel. And I don't want that, I want to keep my Office 365 with the version 17XX.
It seems that there's a new channel called Extended Channel that keeps the version 17XX.

Can you please help me out and explain me how I can change to this channel?

Thanks.

I read the link you sent me, but please have a look at this link: Update history for Office 365 ProPlus (listed by date) | Microsoft Docs

"FirstReleaseCurrent" is the version 1807
"Current" is the version 1806
"FirstReleaseDeferred "is the version 1803
"Deferred" is also the version 1803

What's the channel name for the "second deferred" version 1703 indicated there?

Thanks.