When you sign up as a site owner on Offsite, you'll be asked to select the Google Ads Account you want to connect. After that you'll select the audiences you want to add to OffSite. Any audiences you see in this setup process are visible to Offsite, but they can't be used by the app until you enable Remarketing List Access in Google Ads.
First, let's do some quick house-keeping in Google Ads to make sure that OffSite will be able to actually allow advertisers to use your audience. In your Google Ads account, follow these steps:
1. Sign in to the Google Ads account you used when creating your site owner account on Offsite.
2. In the upper right corner of the account, click the tools icon (it looks like a wrench).
3. Under “Shared library,” click Audience manager.
4. From the page menu on the left, select Settings.
5. Under “Remarketing list access,” click the toggle to share your remarketing lists. A blue toggle indicates that list sharing is on, while a grey toggle indicates that list sharing is off.
If this isn't toggled on, OffSite won't be able to connect your audience to advertisers, even if you can see your audience in OffSite.