How do Robinhood's limit orders work for pre-IPO shares?

I am confused by Robinhood IPO access. On one side, https://robinhood.com/us/en/support/articles/preipo-trading/ states:

We offer pre-IPO orders for a small selection of stocks, and won’t support pre-IPO orders for every company that lists on the market.

These orders are limit orders only, which means we can’t guarantee your order will get filled.

which sounds like it is just a regular limit order on the secondary market.

But at the same time, those limit orders must be passed much before the market open according to the Robinhood application:

SpaceX: $135.00. IPO Access listing.

Price has been finalized. Edit or cancel your

request by June 11, 2026 at 8:59 PM PDT.

and flipping is discouraged:

You can sell the shares you received through IPO access at any point in time. However, if you sell IPO shares within 30 days of the IPO, it's considered flipping and you may be prevented from participating in IPO access for 60 days. This policy applies to all IPOs offered with IPO access.

so it doesn't sound like a regular limit order on the secondary market.

Therefore, I am confused. How do Robinhood's limit orders work for pre-IPO shares?