Skip Ahead Invites??

You must be invited to become an Alpha Insider or Alpha Skip Ahead Insider, to do so You must Very active in Xbox, doing missions and report the bugs You see in the system, as much as You do this, so You Will be Very close to become an Alpha Insider. You
must be at least in Delta preview to become an Alpha Insider, but You Just need to be an Insider to be invited to become an Alpha Skip Ahead, but this one is very rare to be invited and there is a certain number of people to be invited, no more than that,
If You were not invited to be Alpha Skip Ahead certain time, so You must wait a Second chance when they Will invite New members.

You dont apply for skip ahead you get invites

Alpha is application

Hi

Unfortunately once the Alpha Skip ahead tier reached capacity and they had to stop accepting additional new members. When the invites were sent out there would have been places available in the Alpha Skip ahead group however once these
places filled up no additional members (even with invites) could join at this group.

https://news.xbox.com/en-us/2018/06/29/alpha-skip-ahead-registrations-closed/

Keep in mind you cannot re enroll into skip ahead if you remove from it

As its invite only

You don't first there is the alpha which you can join for alphas

And there is the skip ahead keep in mind it's also the most buggy since it is the first relEASE

And you have to get an invite for skip ahead the only way to get into that is by doing a lot of feedback on the other rings and you will get sn invite eventually even they have room and based on your feedback