Prototype

Yes - it is still available  :: you can do it in Portal  ::

 But, you need 4 people for the elevator ; they must have a phantom skin and a phantom tag ; each person should have a different tag on (which skin doens't matter)

You can ask for help on this Discord channel

https://discord.com/channels/239788202745921536/1408121992397459576

your Link is "korrupt" , Discord open's but nothing else. No chat, nothing......???

Maybe you have to be a member

Try this site ::: https://bfee.co/

it is a site dedicate the finding the 'easter eggs' in battlefield games 

then join their Discord channel

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Here is an 'invite' for you :::   https://discord.gg/bfee