You can check .onion links without TOR by adding a .to to the domain.
Like this: https://www.theboxmmvl6zg3wi.onion.to/?ID=57739907578e

Also, well, the OP clearly states
my incredible inference skills tell me this is a "forum posting job".

Anyway, I do not see the point on doing these things anonymously... if you are not doing something illegal, why would you want to hide your identity? (for example, you won't be able to put this -kind of jobs- in your portfolio). The payment is not that impressive either, specially if the job is full-time (It would be good to have more details, but well, HumanResources never discloses the jobs openly...).