To retarget a link on Facebook, you can create a Facebook retargeting campaign using the Facebook Ads Manager. Here are the steps to follow:

Create a Custom Audience: Go to the Audiences section in the Facebook Ads Manager and create a Custom Audience based on website traffic. Choose the specific website URL you want to retarget and select the time frame for the retargeting.

Create a Campaign: Go to the Campaigns section in the Facebook Ads Manager and create a new campaign. Choose the objective of the campaign, such as website traffic or conversions.

Set Ad Set Targeting: In the Ad Set section of the campaign, set the targeting for the retargeting campaign. Select the Custom Audience you created in Step 1 as the target audience.

Create an Ad: In the Ad section of the campaign, create an ad that includes a link to the page you want to retarget. Choose the ad format that best suits your needs, such as a single image ad or a video ad.

Launch the Campaign: Review the campaign settings and launch the retargeting campaign.

Once the retargeting campaign is launched, Facebook will show the ad to people who have previously visited the specific website URL you selected in the Custom Audience. This can be an effective way to reach people who have already shown an interest in your product or service, and encourage them to return to your website and take action.