I'd suggest first contacting your local PMI Chapter as many of them do have job boards.
Also, as a volunteer moderator of PMI's LinkedIn Project, Program and Portfolio Management discussion group, we do periodically pin a discussion thread where members can post jobs. These are not permitted normally, so you'd have to keep your eyes open for when that window of opportunity opens.
Most job platforms allow filtering jobs by role. So, when configuring the job post, be careful to specify "Project Manager" role. People that search for this position will find your employment advertisement. Saving Changes...