[Duller-Finite]

While you're right they edited the embryos the sentence you quoted is describing a drug (680C91) that they bath-applied to inhibit the TDO enzyme (as a positive control), rather than the CRISPR strategy they used, in which they injected the Cas9 and sgRNA into the embryo.

[T-A]

Oops, I should have quoted this part, from the summary:

Knocking out TDO in squid embryos efficiently eliminated pigmentation. By precisely timing CRISPR-Cas9 delivery during early development, the degree of pigmentation could be finely controlled.