Research advertising as a recruitment method
First step:

Make sure your relevant regulatory committee (for example, an Institutional Review Board/IRB in the US) approves of the language in the advertisement. Example guidance from my institution that makes it clear the IRB needs to approve of your advertisement:

https://kb.wisc.edu/hsirbs/page.php?id=29560


  IRBs will consider whether recruitment processes, including advertisements could affect the equitable selection of participants, or be unduly coercive or misleading. IRBs will consider the content, design and mode of communication of any advertisements in making this determination.


Don't skip step 1.

The rest of the steps are outside the scope of Academia.SE, but involve contacting whoever manages the advertising in the venue you are posting to.