The message given on the challenge page:
Time for lunch. Hope you like pactf{🍟 🐟🐟🐟🐟 🐟 🐟🐟🍟🐟 🐟🐟 🐟🐟🐟 🐟🐟🐟🐟 🍟🍟 🐟🐟🍟 🐟🐟🐟 🍟 🍟🐟🐟🐟 🐟 🐟🐟🐟🐟 🐟🍟 🍟🐟🐟 🍟🐟🐟 🍟🍟🍟 🍟🐟🍟🐟 🍟🐟🍟}!
All lowercase, and no spaces.
Very simple substitution, replacing 🍟 with - and 🐟 with . gives us morse code:
pactf{- .... . ..-. .. ... .... -- ..- ... - -... . .... .- -.. -.. --- -.-. -.-}
Decoded to ASCII:
pactf{THEFISHMUSTBEHADDOCK}