According to the official announcement from Arknights:

All Endministrators who complete the main mission [Chapter Ⅰ Process I: Break the Siege] shall receive a progress reward: [Designation Selection Permit]×1. Use this permit to designate and acquire one of the 6★ operators featured in the Basic Headhunting banner.

Select ticket acquisition time: After the maintenance on February 5, 2026, it will be sent by email.

Check the news link: Arknights: Endfield Zeroth Directive: DEV Comm

The selectable characters are:

Other updates include the reduction of enemy levels in high-exploration levels, which lowers the game difficulty.

The news also mentions some interesting information:

As of February 1, 2026, the total length of power lines transported by global Administrators has reached 42,195,240,313m; a total of 23,271,228 shared devices have been maintained, among which the most placed and maintained by Administrators is a convenience access station located in the hub area of Valley 4, which has been maintained 4,342,952 times so far. Thank you for your joint construction and support, global Administrators!

For players, this is a good opportunity to get a powerful operator.