Somewhere on the job post there is an email address you need to contact for further information. I just sent an email today requesting the shop information and requirements.
Good Luck
Are you sending in the W9 before a job pops up you are interested in? There is one solution to use a TaxID. They are created by the IRS and this number can be used in place of your Social Security Number. You can get one in Minutes. I have one that I use for Mystery Shopping and on line sales companies like Ebay and Mercari.
Jobs go very quickly! Make sure to update your notifications so that you are able to respond quickly.!