The Free Fire OB23 Advance Server was scheduled to be released on 15th July 2020, ie, two days back, but has not been done so yet. The developers, Garena, have now revealed the reason for the same, and made an important announcement regarding the fate of its release as well.
Free Fire OB23 Advance Server release

Garena Free Fire has announced that they will not be releasing the OB23 Advance Server because of some technical issues.
It means that the next big update will be released directly, and that players will not be able to enjoy the features in advance and report bugs, though the devs have ensured that it will not impact the release of the Free Fire OB23 update. The announcement was made on Garena's official Facebook handle:
Advanced server has been canceled due to technical issues we encountered in the server opening phase. It's important to say that this cancellation will not impact the arrival of the next game update. We apologize for what happened.
The website of the Advance Server has also been brought down, as you can see in the image below:

The Free Fire OB23 update will be released at the end of this month, with the expected arrival date set for 29th July 2020. According to various leaks, the update will bring a new character called Lucas, the Bermuda 2.0 map, a pet penguin, an AUG Gun and much more.
The servers will be taken down for maintenance, and the update will be available to download from Google Play Store and Apple Store.
Meanwhile, Free Fire has unveiled the new weapon royale — Captain Bubbles M60 — and here is the teaser shared on YouTube:
Also read: Free Fire OB23 update - New Bermuda 2.0 map leaked
Check out the latest Free Fire MAX redeem codes here.