Greenhouse Recruiting has integrations that create free job posts on Indeed after you set your external job posts live. These can be configured at the bottom of each job's edit page or when bulk editing external job posts.
Enable a free job post on Indeed
Click the Jobs tab at the top of any page, then select a job from the list.
From the Job Dashboard, click on Job Setup on the left side of the page.
Find the Job Posts section, then click Edit.
On the Job Posts page, click the Edit icon 
next to the job post you want to submit to Indeed.
On the Edit Your Job Post page, scroll down to the Publish to Free Job Boards section. Click the checkbox next to Indeed.
Then, enter a city for Indeed to use to index the job. If the job is remote, click the checkbox next to Remote.
When you finish, click Save.
Once the job post is live, the job's information is sent to Indeed. To learn about how Indeed promotes job posts, click here.
Indeed salary estimates
When you're posting jobs to Indeed and don't include salary information, Indeed will automatically include an estimated salary. For more information about this feature, contact Indeed's customer support.
Refresh a free job post on Indeed
Websites like Indeed can be a great resource for new candidates when your job posts are first posted online, but over time, your posts can become stale and lose visibility to newer posts.
Because Indeed offers sponsored posts for better positioning on their site, it is not possible to repost a job ad in Greenhouse Recruiting to generate a new ad on Indeed. Taking the post down and then reactivating it, or closing and reopening the job will simply re-post the stale job instead of creating a new one.
Websites like Indeed also have filters that check for similar job titles and descriptions to hide duplicates, so creating a new job in order to generate a new ad is also likely to fail.