Hi! Have a look here:
https://wpjobmanager.com/document/single-job-listings/
The key part for you:
If you encounter issues with your single job listing page, or want to remove something added by your theme (for example meta/author information beneath a post) you can create a new template file in your theme named single-job_listing.php based on your single.php and edit that.
So in that single-job_listing.php you can add the code to display the sidebar that you want.