Seems like morse code. Decoding with a morse code audio decoder gets the following:

THE KEY IS HACKTHEPLANET
(spacing unknown)

Search through the forums a little bit for a hint! Check out [https://ghosttown.deadface.io/t/rendezvous-lets-goooooo/127/4](http://) for the encrypted date as a png.
Reverse image solve indicates it's an *HIBC PAS Codablock-F barcode.*
After lots of searching, I finally found this site: [https://products.aspose.app/barcode/recognize#/recognized](http://)
Decrypts the barcode as YEOOFIIGEHRJBMTJYYUSKPMOIK
Decrypt with Vigenere's with HACKTHEPLANET as the key to get REMEMBERTHEFIFTHOFNOVEMBER

flag{NOVEMBER-5}